Merge branch 'frame_nav_events' of github.com:Akylas/NativeScript

# Conflicts:
#	apps/automated/src/test-runner.ts
#	packages/core/css/parser.ts
#	packages/core/global-types.d.ts
#	packages/core/ui/bottom-navigation/index.android.ts
#	packages/core/ui/styling/style-scope.ts
#	packages/core/ui/tabs/index.android.ts
#	packages/core/ui/tabs/index.ios.ts

.eslintrc.json

@@ -4,15 +4,27 @@
 	"parserOptions": {
 		"ecmaVersion": 2018,
 		"sourceType": "module",
-		"project": "./tsconfig.json"
+		"project": ["packages/core/tsconfig.json", "packages/webpack/tsconfig.json"]
 	},
 	"ignorePatterns": ["**/*"],
 	"plugins": ["@typescript-eslint", "@nrwl/nx"],
-	"extends": ["eslint:recommended", "plugin:@typescript-eslint/eslint-recommended", "plugin:@typescript-eslint/recommended", "prettier", "prettier/@typescript-eslint"],
+	"extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended", "prettier", "prettier/@typescript-eslint"],
 	"rules": {
 		"@typescript-eslint/explicit-member-accessibility": "off",
 		"@typescript-eslint/explicit-function-return-type": "off",
 		"@typescript-eslint/no-parameter-properties": "off",
+		"@typescript-eslint/no-empty-function": "off",
+		"@typescript-eslint/no-explicit-any": "off",
+		"@typescript-eslint/no-unused-vars": "off",
+		"@typescript-eslint/no-namespace": "off",
+		"@typescript-eslint/ban-types": "off",
+		"@typescript-eslint/ban-ts-comment": "off",
+		"@typescript-eslint/no-this-alias": "off",
+		"@typescript-eslint/no-empty-interface": "off",
+		"@typescript-eslint/triple-slash-reference": "off",
+		"no-prototype-builtins": "off",
+		"no-inner-declarations": "off",
+		"no-constant-condition": "off",
 		"@nrwl/nx/enforce-module-boundaries": [
 			"error",
 			{

apps/automated/src/test-runner.ts

@@ -309,11 +309,10 @@ export function isRunningOnEmulator(): boolean {
 	if (tempTest) {
 		allTests[singleTest] = tempTest;
 	} else {
-			console.log("Test does not exist", singleTest);
+		console.log('Test does not exist', singleTest);
 	}
 }
 
-
 const testsSuitesWithLongDelay = {
 	HTTP: 15 * 1000,
 };
@@ -442,6 +441,15 @@ function log(): void {
 	TKUnit.write(testsName + ' COMPLETED for ' + duration.toFixed(2) + ' BACKSTACK DEPTH: ' + Frame.topmost().backStack.length, Trace.messageType.info);
 }
 
+function getAllProperties(obj: any) {
+	let properties = new Set<string>();
+	let currentObj = obj;
+	do {
+		Object.getOwnPropertyNames(currentObj).map((item) => properties.add(item));
+	} while ((currentObj = Object.getPrototypeOf(currentObj)) && currentObj !== Object.prototype);
+	return [...properties.keys()];
+}
+
 let testsSelector: string;
 export function runAll(testSelector?: string) {
 	testsSelector = testSelector;
@@ -496,7 +504,7 @@ export function runAll(testSelector?: string) {
 			testsQueue.push(new TestInfo(test.setUpModule, test));
 		}
 
-		for (const testName in test) {
+		for (const testName of getAllProperties(test)) {
 			if (singleTestName && singleTestName !== testName.toLowerCase()) {
 				continue;
 			}

apps/automated/src/ui/date-picker/date-picker-tests.ts

@@ -1,8 +1,8 @@
 import * as TKUnit from '../../tk-unit';
 import * as testModule from '../../ui-test';
 import * as datePickerTestsNative from './date-picker-tests-native';
-import * as color from '@nativescript/core/color';
 import * as platform from '@nativescript/core/platform';
+import { Color } from '@nativescript/core';
 
 // >> date-picker-require
 import * as datePickerModule from '@nativescript/core/ui/date-picker';
@@ -77,10 +77,13 @@ export class DatePickerTest extends testModule.UITest<datePickerModule.DatePicke
 
 	public test_set_color() {
 		if (platform.Device.os === platform.platformNames.ios) {
-			this.testView.color = new color.Color('red');
+			const SUPPORT_TEXT_COLOR = parseFloat(platform.Device.osVersion) < 14.0;
+			if (SUPPORT_TEXT_COLOR) {
+				this.testView.color = new Color('red');
 				TKUnit.assertEqual(this.testView.color.ios.CGColor, this.testView.ios.valueForKey('textColor').CGColor, 'datePicker.color');
 			}
 		}
+	}
 
 	public test_WhenCreated_YearIsCurrentYear() {
 		const actualValue = this.testView.year;

apps/automated/src/ui/list-view/list-view-tests.ts

@@ -608,7 +608,7 @@ export class ListViewTest extends UITest<ListView> {
 
 		if (isAndroid) {
 			// simulates Angular way of removing views
-			(<any>listView)._realizedItems.forEach((view, nativeView, map) => {
+			(<any>listView)._realizedItems.forEach(({ view }, nativeView, map) => {
 				//console.log("view: " + view);
 				listView._removeView(view);
 			});
@@ -902,6 +902,29 @@ export class ListViewTest extends UITest<ListView> {
 		TKUnit.assertEqual(secondNativeElementText, 'green', 'second element text');
 	}
 
+	public test_ItemTemplateSelector_DoesNotThrowWhenItemsChangeMidRender() {
+		let listView = this.testView;
+		listView.height = 200;
+
+		listView.itemTemplates = this._itemTemplatesString;
+		listView.itemTemplateSelector = "age === 0 ? 'red' : 'green'";
+		listView.items = ListViewTest.generateItemsForMultipleTemplatesTests(4);
+		listView.items[0].age = 0;
+		listView.once('itemLoading', () => {
+			if (listView.items && listView.items.length) {
+				listView.items[0].age = listView.items[0].age !== 0 ? 0 : 1;
+			}
+		});
+		listView.refresh();
+		TKUnit.wait(0.1);
+		listView.scrollToIndex(1);
+		TKUnit.wait(0.1);
+		listView.scrollToIndex(2);
+		TKUnit.wait(0.1);
+		listView.scrollToIndex(3);
+		TKUnit.wait(0.1);
+	}
+
 	public test_ItemTemplateSelector_TestVirtualization() {
 		let listView = this.testView;
 		listView.height = 300;

apps/automated/src/ui/time-picker/time-picker-tests.ts

@@ -1,9 +1,9 @@
 import * as TKUnit from '../../tk-unit';
 import * as testModule from '../../ui-test';
 import * as timePickerTestsNative from './time-picker-tests-native';
-import * as color from '@nativescript/core/color';
 import * as platform from '@nativescript/core/platform';
 import * as helper from '../../ui-helper';
+import { Color } from '@nativescript/core';
 
 // >> require-time-picker
 import * as timePickerModule from '@nativescript/core/ui/time-picker';
@@ -50,10 +50,13 @@ export class TimePickerTest extends testModule.UITest<timePickerModule.TimePicke
 	// Supported in iOS only.
 	public test_set_color() {
 		if (platform.Device.os === platform.platformNames.ios) {
-			this.testView.color = new color.Color('red');
+			const SUPPORT_TEXT_COLOR = parseFloat(platform.Device.osVersion) < 14.0;
+			if (SUPPORT_TEXT_COLOR) {
+				this.testView.color = new Color('red');
 				TKUnit.assertEqual(this.testView.color.ios.CGColor, this.testView.ios.valueForKey('textColor').CGColor, 'timePicker.color');
 			}
 		}
+	}
 
 	public test_WhenCreated_MinuteIntervalIs1() {
 		let actualValue = this.testView.minuteInterval;

packages/core/__tests__/css/parser.ts

@@ -278,8 +278,8 @@ describe('css', () => {
 					const cssparser = new CSS3Parser(themeCoreLightIos);
 					const stylesheet = cssparser.tokenize();
 
-					let original = themeCoreLightIos.replace(/\/\*([^\/]|\/[^\*])*\*\//g, '').replace(/\n/g, ' ');
-					let roundtrip = stylesheet
+					const original = themeCoreLightIos.replace(/\/\*([^\/]|\/[^\*])*\*\//g, '').replace(/\n/g, ' ');
+					const roundtrip = stylesheet
 						.map((m) => {
 							if (!m) {
 								return '';
@@ -293,8 +293,8 @@ describe('css', () => {
 						})
 						.join('');
 
-					let lastIndex = Math.min(original.length, roundtrip.length);
-					for (var i = 0; i < lastIndex; i++) {
+					const lastIndex = Math.min(original.length, roundtrip.length);
+					for (let i = 0; i < lastIndex; i++) {
 						if (original[i] !== roundtrip[i]) {
 							assert.equal(roundtrip.substr(i, 50), original.substr(i, 50), 'Round-tripped CSS string differ at index: ' + i);
 						}

packages/core/__tests__/observable/observable.ts

@@ -5,7 +5,7 @@ describe('observable', () => {
 	describe('once', () => {
 		let observable: Observable;
 		let handler: () => void;
-		let callCount: number = 0;
+		let callCount = 0;
 
 		beforeEach('create handlers', () => {
 			handler = function () {

packages/core/__tests__/ui/styling/css-selector.ts

@@ -21,30 +21,30 @@ describe('ui', () => {
 					);
 				});
 
-				function create(css: string, source: string = 'css-selectors.ts@test'): { rules: selector.RuleSet[]; map: selector.SelectorsMap<any> } {
-					let parse = parser.parse(css, { source });
-					let rulesAst = parse.stylesheet.rules.filter((n) => n.type === 'rule');
-					let rules = selector.fromAstNodes(rulesAst);
-					let map = new selector.SelectorsMap(rules);
+				function create(css: string, source = 'css-selectors.ts@test'): { rules: selector.RuleSet[]; map: selector.SelectorsMap<any> } {
+					const parse = parser.parse(css, { source });
+					const rulesAst = parse.stylesheet.rules.filter((n) => n.type === 'rule');
+					const rules = selector.fromAstNodes(rulesAst);
+					const map = new selector.SelectorsMap(rules);
 
 					return { rules, map };
 				}
 
-				function createOne(css: string, source: string = 'css-selectors.ts@test'): selector.RuleSet {
-					let { rules } = create(css, source);
+				function createOne(css: string, source = 'css-selectors.ts@test'): selector.RuleSet {
+					const { rules } = create(css, source);
 					assert.equal(rules.length, 1);
 
 					return rules[0];
 				}
 
 				it('single selector', () => {
-					let rule = createOne(`* { color: red; }`);
+					const rule = createOne(`* { color: red; }`);
 					assert.isTrue(rule.selectors[0].match({ cssType: 'button' }));
 					assert.isTrue(rule.selectors[0].match({ cssType: 'image' }));
 				});
 
 				it('two selectors', () => {
-					let rule = createOne(`button, image { color: red; }`);
+					const rule = createOne(`button, image { color: red; }`);
 					assert.isTrue(rule.selectors[0].match({ cssType: 'button' }));
 					assert.isTrue(rule.selectors[1].match({ cssType: 'image' }));
 					assert.isFalse(rule.selectors[0].match({ cssType: 'stacklayout' }));
@@ -52,24 +52,24 @@ describe('ui', () => {
 				});
 
 				it('narrow selection', () => {
-					let { map } = create(`
+					const { map } = create(`
                         .login { color: blue; }
                         button { color: red; }
                         image { color: green; }
                     `);
 
-					let buttonQuerry = map.query({ cssType: 'button' }).selectors;
+					const buttonQuerry = map.query({ cssType: 'button' }).selectors;
 					assert.equal(buttonQuerry.length, 1);
 					assert.includeDeepMembers(buttonQuerry[0].ruleset.declarations, [{ property: 'color', value: 'red' }]);
 
-					let imageQuerry = map.query({ cssType: 'image', cssClasses: new Set(['login']) }).selectors;
+					const imageQuerry = map.query({ cssType: 'image', cssClasses: new Set(['login']) }).selectors;
 					assert.equal(imageQuerry.length, 2);
 					// Note class before type
 					assert.includeDeepMembers(imageQuerry[0].ruleset.declarations, [{ property: 'color', value: 'green' }]);
 					assert.includeDeepMembers(imageQuerry[1].ruleset.declarations, [{ property: 'color', value: 'blue' }]);
 				});
 
-				let positiveMatches = {
+				const positiveMatches = {
 					'*': (view) => true,
 					type: (view) => view.cssType === 'type',
 					'#id': (view) => view.id === 'id',
@@ -79,7 +79,7 @@ describe('ui', () => {
 					"[src2='src-value']": (view) => view['src2'] === 'src-value',
 				};
 
-				let positivelyMatchingView = {
+				const positivelyMatchingView = {
 					cssType: 'type',
 					id: 'id',
 					cssClasses: new Set(['class']),
@@ -88,7 +88,7 @@ describe('ui', () => {
 					src2: 'src-value',
 				};
 
-				let negativelyMatchingView = {
+				const negativelyMatchingView = {
 					cssType: 'nottype',
 					id: 'notid',
 					cssClasses: new Set(['notclass']),
@@ -98,9 +98,9 @@ describe('ui', () => {
 				};
 
 				it('simple selectors match', () => {
-					for (let sel in positiveMatches) {
-						let css = sel + ' { color: red; }';
-						let rule = createOne(css);
+					for (const sel in positiveMatches) {
+						const css = sel + ' { color: red; }';
+						const rule = createOne(css);
 						assert.isTrue(rule.selectors[0].match(positivelyMatchingView), 'Expected successful match for: ' + css);
 						if (sel !== '*') {
 							assert.isFalse(rule.selectors[0].match(negativelyMatchingView), 'Expected match failure for: ' + css);
@@ -109,11 +109,11 @@ describe('ui', () => {
 				});
 
 				it('two selector sequence positive match', () => {
-					for (let firstStr in positiveMatches) {
-						for (let secondStr in positiveMatches) {
+					for (const firstStr in positiveMatches) {
+						for (const secondStr in positiveMatches) {
 							if (secondStr !== firstStr && secondStr !== '*' && secondStr !== 'type') {
-								let css = firstStr + secondStr + ' { color: red; }';
-								let rule = createOne(css);
+								const css = firstStr + secondStr + ' { color: red; }';
+								const rule = createOne(css);
 								assert.isTrue(rule.selectors[0].match(positivelyMatchingView), 'Expected successful match for: ' + css);
 								if (firstStr !== '*') {
 									assert.isFalse(rule.selectors[0].match(negativelyMatchingView), 'Expected match failure for: ' + css);
@@ -124,7 +124,7 @@ describe('ui', () => {
 				});
 
 				it('direct parent combinator', () => {
-					let rule = createOne(`listview > item:selected { color: red; }`);
+					const rule = createOne(`listview > item:selected { color: red; }`);
 					assert.isTrue(
 						rule.selectors[0].match({
 							cssType: 'item',
@@ -151,7 +151,7 @@ describe('ui', () => {
 				});
 
 				it('ancestor combinator', () => {
-					let rule = createOne(`listview item:selected { color: red; }`);
+					const rule = createOne(`listview item:selected { color: red; }`);
 					assert.isTrue(
 						rule.selectors[0].match({
 							cssType: 'item',
@@ -191,8 +191,8 @@ describe('ui', () => {
 				});
 
 				it('backtracking css selector', () => {
-					let sel = createOne(`a>b c { color: red; }`).selectors[0];
-					let child = {
+					const sel = createOne(`a>b c { color: red; }`).selectors[0];
+					const child = {
 						cssType: 'c',
 						parent: {
 							cssType: 'b',
@@ -216,7 +216,7 @@ describe('ui', () => {
 				}
 
 				it('simple query match', () => {
-					let { map } = create(`list grid[promotion] button:highlighted { color: red; }`);
+					const { map } = create(`list grid[promotion] button:highlighted { color: red; }`);
 
 					let list, grid, button;
 
@@ -235,16 +235,16 @@ describe('ui', () => {
 						},
 					};
 
-					let match = map.query(button);
+					const match = map.query(button);
 					assert.equal(match.selectors.length, 1, 'Expected match to have one selector.');
 
-					let expected = new Map<selector.Node, selector.Changes>().set(grid, { attributes: new Set(['promotion']) }).set(button, { pseudoClasses: new Set(['highlighted']) });
+					const expected = new Map<selector.Node, selector.Changes>().set(grid, { attributes: new Set(['promotion']) }).set(button, { pseudoClasses: new Set(['highlighted']) });
 
 					assert.deepEqual(match.changeMap, expected);
 				});
 
 				it('query match one child group', () => {
-					let { map } = create(`#prod[special] > gridlayout { color: red; }`);
+					const { map } = create(`#prod[special] > gridlayout { color: red; }`);
 					let gridlayout, prod;
 
 					gridlayout = {
@@ -257,15 +257,15 @@ describe('ui', () => {
 						},
 					};
 
-					let match = map.query(gridlayout);
+					const match = map.query(gridlayout);
 					assert.equal(match.selectors.length, 1, 'Expected match to have one selector.');
 
-					let expected = new Map<selector.Node, selector.Changes>().set(prod, { attributes: new Set(['special']) });
+					const expected = new Map<selector.Node, selector.Changes>().set(prod, { attributes: new Set(['special']) });
 					assert.deepEqual(match.changeMap, expected);
 				});
 
 				it('query match one sibling group (deepEqual does not compare Map?)', () => {
-					let { map } = create(`list button:highlighted+button:disabled { color: red; }`);
+					const { map } = create(`list button:highlighted+button:disabled { color: red; }`);
 					let list, button, disabledButton;
 
 					list = {
@@ -289,10 +289,10 @@ describe('ui', () => {
 						parent: list,
 					};
 
-					let match = map.query(disabledButton);
+					const match = map.query(disabledButton);
 					assert.equal(match.selectors.length, 1, 'Expected match to have one selector.');
 
-					let expected = new Map<selector.Node, selector.Changes>().set(disabledButton, { pseudoClasses: new Set(['disabled']) }).set(button, { pseudoClasses: new Set(['highlighted']) });
+					const expected = new Map<selector.Node, selector.Changes>().set(disabledButton, { pseudoClasses: new Set(['disabled']) }).set(button, { pseudoClasses: new Set(['highlighted']) });
 
 					assert.deepEqual(match.changeMap, expected);
 				});

packages/core/animation-frame/index.ts

@@ -1,12 +1,18 @@
+import { queueMacrotask } from '../utils/macrotask-scheduler';
 import { FPSCallback } from '../fps-meter/fps-native';
 import { getTimeInFrameBase } from './animation-native';
+import { Trace } from 'trace';
 
 export interface FrameRequestCallback {
 	(time: number): void;
 }
 
+type AnimationFrameCallbacks = { [key: string]: FrameRequestCallback };
+
 let animationId = 0;
-let nextFrameAnimationCallbacks: { [key: string]: FrameRequestCallback } = {};
+let currentFrameAnimationCallbacks: AnimationFrameCallbacks = {}; // requests that were scheduled in this frame and must be called ASAP
+let currentFrameScheduled = false;
+let nextFrameAnimationCallbacks: AnimationFrameCallbacks = {}; // requests there were scheduled in another request and must be called in the next frame
 let shouldStop = true;
 let inAnimationFrame = false;
 let fpsCallback: FPSCallback;
@@ -23,33 +29,59 @@ function ensureNative() {
 	fpsCallback = new FPSCallback(doFrame);
 }
 
+function callAnimationCallbacks(thisFrameCbs: AnimationFrameCallbacks, frameTime: number): void {
+	inAnimationFrame = true;
+	for (const animationId in thisFrameCbs) {
+		if (thisFrameCbs[animationId]) {
+			try {
+				thisFrameCbs[animationId](frameTime);
+			} catch (err) {
+				const msg = err ? err.stack || err : err;
+				Trace.write(`Error in requestAnimationFrame: ${msg}`, Trace.categories.Error, Trace.messageType.error);
+			}
+		}
+	}
+	inAnimationFrame = false;
+}
+
+function doCurrentFrame() {
+	// if we're not getting accurate frame times
+	// set last frame time as the current time
+	if (!fpsCallback || !fpsCallback.running) {
+		lastFrameTime = getTimeInFrameBase();
+	}
+	currentFrameScheduled = false;
+	const thisFrameCbs = currentFrameAnimationCallbacks;
+	currentFrameAnimationCallbacks = {};
+	callAnimationCallbacks(thisFrameCbs, lastFrameTime);
+}
+
 function doFrame(currentTimeMillis: number) {
 	lastFrameTime = currentTimeMillis;
 	shouldStop = true;
 	const thisFrameCbs = nextFrameAnimationCallbacks;
 	nextFrameAnimationCallbacks = {};
-	inAnimationFrame = true;
-	for (const animationId in thisFrameCbs) {
-		if (thisFrameCbs[animationId]) {
-			thisFrameCbs[animationId](lastFrameTime);
-		}
-	}
-	inAnimationFrame = false;
+	callAnimationCallbacks(thisFrameCbs, lastFrameTime);
 	if (shouldStop) {
 		fpsCallback.stop(); // TODO: check performance without stopping to allow consistent frame times
 	}
 }
 
-export function requestAnimationFrame(cb: FrameRequestCallback): number {
-	if (!inAnimationFrame) {
-		inAnimationFrame = true;
-		zonedCallback(cb)(getTimeInFrameBase()); // TODO: store and use lastFrameTime
-		inAnimationFrame = false;
+function ensureCurrentFrameScheduled() {
+	if (!currentFrameScheduled) {
+		currentFrameScheduled = true;
+		queueMacrotask(doCurrentFrame);
+	}
+}
 
-		return getNewId();
+export function requestAnimationFrame(cb: FrameRequestCallback): number {
+	const animId = getNewId();
+	if (!inAnimationFrame) {
+		ensureCurrentFrameScheduled();
+		currentFrameAnimationCallbacks[animId] = zonedCallback(cb) as FrameRequestCallback;
+		return animId;
 	}
 	ensureNative();
-	const animId = getNewId();
 	nextFrameAnimationCallbacks[animId] = zonedCallback(cb) as FrameRequestCallback;
 	shouldStop = false;
 	fpsCallback.start();
@@ -57,6 +89,7 @@ export function requestAnimationFrame(cb: FrameRequestCallback): number {
 	return animId;
 }
 
-export function cancelAnimationFrame(id: number) {
+export function cancelAnimationFrame(id: number): void {
+	delete currentFrameAnimationCallbacks[id];
 	delete nextFrameAnimationCallbacks[id];
 }

packages/core/application-settings/index.android.ts

@@ -96,7 +96,7 @@ export function getAllKeys(): Array<string> {
 	const iterator = mappedPreferences.keySet().iterator();
 	const result = [];
 	while (iterator.hasNext()) {
-		let key = iterator.next();
+		const key = iterator.next();
 		result.push(key);
 	}
 

packages/core/application/application-common.ts

@@ -8,7 +8,6 @@ import { EventData } from '../data/observable';
 import { View } from '../ui/core/view';
 
 // Requires
-import { Observable } from '../data/observable';
 import * as bindableResources from '../ui/core/bindable/bindable-resources';
 import { CSSUtils } from '../css/system-classes';
 import { Enums } from '../ui/enums';
@@ -34,7 +33,7 @@ const ORIENTATION_CSS_CLASSES = [`${CSSUtils.CLASS_PREFIX}${Enums.DeviceOrientat
 
 const SYSTEM_APPEARANCE_CSS_CLASSES = [`${CSSUtils.CLASS_PREFIX}${Enums.SystemAppearance.light}`, `${CSSUtils.CLASS_PREFIX}${Enums.SystemAppearance.dark}`];
 
-let cssFile: string = './app.css';
+let cssFile = './app.css';
 
 export function getResources() {
 	return bindableResources.get();
@@ -44,8 +43,8 @@ export function setResources(res: any) {
 	bindableResources.set(res);
 }
 
-export let android: AndroidApplication = undefined;
-export let ios: iOSApplication = undefined;
+export const android: AndroidApplication = undefined;
+export const ios: iOSApplication = undefined;
 
 export const on = global.NativeScriptGlobals.events.on.bind(global.NativeScriptGlobals.events);
 export const off = global.NativeScriptGlobals.events.off.bind(global.NativeScriptGlobals.events);

packages/core/application/index.android.ts

@@ -2,8 +2,11 @@
 import { AndroidApplication as AndroidApplicationDefinition } from '.';
 import { AndroidActivityBackPressedEventData, AndroidActivityBundleEventData, AndroidActivityEventData, AndroidActivityNewIntentEventData, AndroidActivityRequestPermissionsEventData, AndroidActivityResultEventData, ApplicationEventData, CssChangedEventData, OrientationChangedEventData, SystemAppearanceChangedEventData } from './application-interfaces';
 
+// TODO: explain why we need to this or remov it
 // Use requires to ensure order of imports is maintained
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const appCommon = require('./application-common');
+
 // First reexport so that app module is initialized.
 export * from './application-common';
 

packages/core/application/index.d.ts

@@ -198,21 +198,6 @@ export function loadAppCss();
  */
 export function addCss(cssText: string, attributeScoped?: boolean): void;
 
-/**
- * This event is raised when application css is changed.
- */
-export function on(event: 'cssChanged', callback: (args: CssChangedEventData) => void, thisArg?: any);
-
-/**
- * Event raised then livesync operation is performed.
- */
-export function on(event: 'livesync', callback: (args: EventData) => void);
-
-/**
- * Removes listener for the specified event name.
- */
-export function off(eventNames: string, callback?: any, thisArg?: any);
-
 /**
  * Call this method to run the application. Important: All code after this method call will not be executed!
  * Compared to start this method won't create Frame as root view.
@@ -226,12 +211,9 @@ export function run(entry?: NavigationEntry | string);
 export function _resetRootView(entry?: NavigationEntry | string);
 
 /**
- * A basic method signature to hook an event listener (shortcut alias to the addEventListener method).
- * @param eventNames - String corresponding to events (e.g. "onLaunch"). Optionally could be used more events separated by `,` (e.g. "onLaunch", "onSuspend").
- * @param callback - Callback function which will be executed when event is raised.
- * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
+ * Removes listener for the specified event name.
  */
-export function on(eventNames: string, callback: (data: any) => void, thisArg?: any);
+export function off(eventNames: string, callback?: any, thisArg?: any);
 
 /**
  * Shortcut alias to the removeEventListener method.
@@ -253,6 +235,34 @@ export function notify(data: any): void;
  */
 export function hasListeners(eventName: string): boolean;
 
+/**
+ * A basic method signature to hook an event listener (shortcut alias to the addEventListener method).
+ * @param eventNames - String corresponding to events (e.g. "onLaunch"). Optionally could be used more events separated by `,` (e.g. "onLaunch", "onSuspend").
+ * @param callback - Callback function which will be executed when event is raised.
+ * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
+ */
+export function on(eventNames: string, callback: (data: any) => void, thisArg?: any);
+
+/**
+ * This event is raised when application css is changed.
+ */
+export function on(event: 'cssChanged', callback: (args: CssChangedEventData) => void, thisArg?: any);
+
+/**
+ * Event raised then livesync operation is performed.
+ */
+export function on(event: 'livesync', callback: (args: EventData) => void);
+
+/**
+ * This event is raised when application css is changed.
+ */
+export function on(event: 'cssChanged', callback: (args: CssChangedEventData) => void, thisArg?: any);
+
+/**
+ * Event raised then livesync operation is performed.
+ */
+export function on(event: 'livesync', callback: (args: EventData) => void);
+
 /**
  * This event is raised on application launchEvent.
  */

packages/core/application/index.ios.ts

@@ -2,7 +2,9 @@
 import { iOSApplication as iOSApplicationDefinition } from '.';
 import { ApplicationEventData, CssChangedEventData, LaunchEventData, LoadAppCSSEventData, OrientationChangedEventData, SystemAppearanceChangedEventData } from './application-interfaces';
 
+// TODO: explain why we need to this or remov it
 // Use requires to ensure order of imports is maintained
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const { displayedEvent, exitEvent, getCssFileName, launchEvent, livesync, lowMemoryEvent, notify, on, orientationChanged, orientationChangedEvent, resumeEvent, setApplication, suspendEvent, systemAppearanceChanged, systemAppearanceChangedEvent } = require('./application-common');
 // First reexport so that app module is initialized.
 export * from './application-common';
@@ -381,7 +383,7 @@ export function getRootView() {
 	return iosApp.rootView;
 }
 
-let started: boolean = false;
+let started = false;
 export function run(entry?: string | NavigationEntry) {
 	mainEntry = typeof entry === 'string' ? { moduleName: entry } : entry;
 	started = true;
@@ -400,11 +402,11 @@ export function run(entry?: string | NavigationEntry) {
 				if (rootController) {
 					const controller = getViewController(rootView);
 					rootView._setupAsRootView({});
-					let embedderDelegate = NativeScriptEmbedder.sharedInstance().delegate;
+					const embedderDelegate = NativeScriptEmbedder.sharedInstance().delegate;
 					if (embedderDelegate) {
 						embedderDelegate.presentNativeScriptApp(controller);
 					} else {
-						let visibleVC = getVisibleViewController(rootController);
+						const visibleVC = getVisibleViewController(rootController);
 						visibleVC.presentViewControllerAnimatedCompletion(controller, true, null);
 					}
 

packages/core/color/color-common.ts

@@ -13,9 +13,9 @@ export class Color implements definition.Color {
 	constructor(color: number);
 	constructor(color: string);
 	constructor(a: number, r: number, g: number, b: number);
-	constructor() {
-		if (arguments.length === 1) {
-			const arg = arguments[0];
+	constructor(...args) {
+		if (args.length === 1) {
+			const arg = args[0];
 			if (types.isString(arg)) {
 				if (isRgbOrRgba(arg)) {
 					this._argb = argbFromRgbOrRgba(arg);
@@ -40,8 +40,8 @@ export class Color implements definition.Color {
 			} else {
 				throw new Error('Expected 1 or 4 constructor parameters.');
 			}
-		} else if (arguments.length === 4) {
-			this._argb = (arguments[0] & 0xff) * 0x01000000 + (arguments[1] & 0xff) * 0x00010000 + (arguments[2] & 0xff) * 0x00000100 + (arguments[3] & 0xff) * 0x00000001;
+		} else if (args.length === 4) {
+			this._argb = (args[0] & 0xff) * 0x01000000 + (args[1] & 0xff) * 0x00010000 + (args[2] & 0xff) * 0x00000100 + (args[3] & 0xff) * 0x00000001;
 		} else {
 			throw new Error('Expected 1 or 4 constructor parameters.');
 		}

packages/core/css/css-tree-parser.ts

@@ -9,7 +9,7 @@ function mapSelectors(selector: string): string[] {
 }
 
 function mapPosition(node, css) {
-	let res: any = {
+	const res: any = {
 		start: {
 			line: node.loc.start.line,
 			column: node.loc.start.column,
@@ -47,7 +47,7 @@ function transformAst(node, css, type = null) {
 	}
 
 	if (node.type === 'Atrule') {
-		let atrule: any = {
+		const atrule: any = {
 			type: node.name,
 		};
 
@@ -86,9 +86,9 @@ function transformAst(node, css, type = null) {
 	}
 
 	if (node.type === 'Rule') {
-		let value = node.prelude.value;
+		const value = node.prelude.value;
 
-		let res: any = {
+		const res: any = {
 			type: type != null ? type : 'rule',
 			declarations: transformAst(node.block, css),
 			position: mapPosition(node, css),
@@ -128,8 +128,8 @@ function transformAst(node, css, type = null) {
 }
 
 export function cssTreeParse(css, source): any {
-	let errors = [];
-	let ast = parse(css, {
+	const errors = [];
+	const ast = parse(css, {
 		parseValue: false,
 		parseAtrulePrelude: false,
 		parseRulePrelude: false,

packages/core/css/parser.ts

@@ -1,4 +1,4 @@
-import { getKnownColor } from "color/known-colors";
+import { getKnownColor } from "../color/known-colors";
 
 export type Parsed<V> = { start: number; end: number; value: V };
 
@@ -54,7 +54,7 @@ export interface BackgroundPosition {
 	text?: string;
 }
 
-const urlRegEx = /\s*url\((?:('|")([^\1]*)\1|([^\)]*))\)\s*/gy;
+const urlRegEx = /\s*url\((?:('|")([^\1]*)\1|([^)]*))\)\s*/gy;
 export function parseURL(text: string, start = 0): Parsed<URL> {
 	urlRegEx.lastIndex = start;
 	const result = urlRegEx.exec(text);
@@ -128,10 +128,10 @@ export function convertHSLToRGBColor(hue: number, saturation: number, lightness:
 	hue /= 60;
 	lightness /= 100;
 
-	let chroma = ((1 - Math.abs(2 * lightness - 1)) * saturation) / 100,
-		X = chroma * (1 - Math.abs((hue % 2) - 1)),
+	const chroma = ((1 - Math.abs(2 * lightness - 1)) * saturation) / 100,
+		X = chroma * (1 - Math.abs((hue % 2) - 1));
 		// Add lightness match to all RGB components beforehand
-		{ m: r, m: g, m: b } = { m: lightness - chroma / 2 };
+	let { m: r, m: g, m: b } = { m: lightness - chroma / 2 };
 
 	if (0 <= hue && hue < 1) {
 		r += chroma;
@@ -212,7 +212,7 @@ export function parseColor(value: string, start = 0, keyword = parseKeyword(valu
 	return parseHexColor(value, start) || parseColorKeyword(value, start, keyword) || parseRGBColor(value, start) || parseRGBAColor(value, start) || parseHSLColor(value, start) || parseHSLAColor(value, start);
 }
 
-const keywordRegEx = /\s*([a-z][\w\-]*)\s*/giy;
+const keywordRegEx = /\s*([a-z][\w-]*)\s*/giy;
 function parseKeyword(text: string, start = 0): Parsed<Keyword> {
 	keywordRegEx.lastIndex = start;
 	const result = keywordRegEx.exec(text);
@@ -237,7 +237,7 @@ export function parseRepeat(value: string, start = 0, keyword = parseKeyword(val
 	return null;
 }
 
-const unitRegEx = /\s*([\+\-]?(?:\d+\.\d+|\d+|\.\d+)(?:[eE][\+\-]?\d+)?)([a-zA-Z]+|%)?\s*/gy;
+const unitRegEx = /\s*([+-]?(?:\d+\.\d+|\d+|\.\d+)(?:[eE][+-]?\d+)?)([a-zA-Z]+|%)?\s*/gy;
 export function parseUnit(text: string, start = 0): Parsed<Unit<string>> {
 	unitRegEx.lastIndex = start;
 	const result = unitRegEx.exec(text);
@@ -743,7 +743,7 @@ export function parseSimpleIdentifierSelector(text: string, start = 0): Parsed<T
 	return { start, end, value };
 }
 
-const attributeSelectorRegEx = /\[\s*([_-\w][_-\w\d]*)\s*(?:(=|\^=|\$=|\*=|\~=|\|=)\s*(?:([_-\w][_-\w\d]*)|"((?:[^\\"]|\\(?:"|n|r|f|\\|0-9a-f))*)"|'((?:[^\\']|\\(?:'|n|r|f|\\|0-9a-f))*)')\s*)?\]/gy;
+const attributeSelectorRegEx = /\[\s*([_-\w][_-\w\d]*)\s*(?:(=|\^=|\$=|\*=|~=|\|=)\s*(?:([_-\w][_-\w\d]*)|"((?:[^\\"]|\\(?:"|n|r|f|\\|0-9a-f))*)"|'((?:[^\\']|\\(?:'|n|r|f|\\|0-9a-f))*)')\s*)?\]/gy;
 export function parseAttributeSelector(text: string, start: number): Parsed<AttributeSelector> {
 	attributeSelectorRegEx.lastIndex = start;
 	const result = attributeSelectorRegEx.exec(text);
@@ -852,12 +852,13 @@ export interface QualifiedRule {
 
 const whitespaceRegEx = /[\s\t\n\r\f]*/gmy;
 
-const singleQuoteStringRegEx = /'((?:[^\n\r\f\']|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)(:?'|$)/gmy; // Besides $n, parse escape
-const doubleQuoteStringRegEx = /"((?:[^\n\r\f\"]|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)(:?"|$)/gmy; // Besides $n, parse escape
+const singleQuoteStringRegEx = /'((?:[^\n\r\f']|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)(:?'|$)/gmy; // Besides $n, parse escape
+const doubleQuoteStringRegEx = /"((?:[^\n\r\f"]|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)(:?"|$)/gmy; // Besides $n, parse escape
 
-const commentRegEx = /(\/\*(?:[^\*]|\*[^\/])*\*\/)/gmy;
-const numberRegEx = /[\+\-]?(?:\d+\.\d+|\d+|\.\d+)(?:[eE][\+\-]?\d+)?/gmy;
-const nameRegEx = /-?(?:(?:[a-zA-Z_]|[^\x00-\x7F]|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))(?:[a-zA-Z_0-9\-]*|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)/gmy;
+const commentRegEx = /(\/\*(?:[^*]|\*[^/])*\*\/)/gmy;
+const numberRegEx = /[+-]?(?:\d+\.\d+|\d+|\.\d+)(?:[eE][+-]?\d+)?/gmy;
+// eslint-disable-next-line no-control-regex
+const nameRegEx = /-?(?:(?:[a-zA-Z_]|[^\x00-\x7F]|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))(?:[a-zA-Z_0-9-]*|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*)/gmy;
 // const nonQuoteURLRegEx = /(:?[^\)\s\t\n\r\f\'\"\(]|\\(?:\$|\n|[0-9a-fA-F]{1,6}\s?))*/gym; // TODO: non-printable code points omitted
 
 type InputToken = '(' | ')' | '{' | '}' | '[' | ']' | ':' | ';' | ',' | ' ' | '^=' | '|=' | '$=' | '*=' | '~=' | '<!--' | '-->' | undefined | /* <EOF-token> */ InputTokenObject | FunctionInputToken | FunctionToken | SimpleBlock | AtKeywordToken;
@@ -1334,7 +1335,7 @@ export class CSS3Parser {
 				case ' ':
 					continue;
 				case '<!--':
-				case '-->':
+				case '-->':{
 					if (this.topLevelFlag) {
 						continue;
 					}
@@ -1345,6 +1346,7 @@ export class CSS3Parser {
 					}
 					continue;
 			}
+			}
 			if ((<InputTokenObject>inputToken).type === TokenObjectType.atKeyword) {
 				this.reconsumeTheCurrentInputToken(inputToken);
 				const atRule = this.consumeAnAtRule();
@@ -1511,17 +1513,19 @@ export class CSS3Parser {
 			}
 			const nextInputToken = this.text[this.nextInputCodePointIndex];
 			switch (nextInputToken) {
-				case ')':
+				case ')':{
 					this.nextInputCodePointIndex++;
 					const end = this.nextInputCodePointIndex;
 					funcToken.text = name + '(' + this.text.substring(start, end);
 
 					return funcToken;
-				default:
+				}
+				default:{
 					const component = this.consumeAComponentValue();
 					if (component) {
 						funcToken.components.push(component);
 					}
+				}
 				// TODO: Else we won't advance
 			}
 		} while (true);

packages/core/data/observable-array/index.ts

@@ -1,3 +1,4 @@
+/* eslint-disable prefer-rest-params */
 import { Observable, EventData } from '../observable';
 import * as types from '../../utils/types';
 
@@ -59,6 +60,7 @@ export class ObservableArray<T> extends Observable {
 		if (arguments.length === 1 && Array.isArray(arguments[0])) {
 			this._array = arguments[0].slice();
 		} else {
+			// eslint-disable-next-line prefer-spread
 			this._array = Array.apply(null, arguments);
 		}
 
@@ -67,7 +69,7 @@ export class ObservableArray<T> extends Observable {
 			object: this,
 			action: ChangeType.Add,
 			index: null,
-			removed: new Array(),
+			removed: [],
 			addedCount: 1,
 		};
 
@@ -92,7 +94,7 @@ export class ObservableArray<T> extends Observable {
 	 * Sets item at specified index.
 	 */
 	setItem(index: number, value: T) {
-		let oldValue = this._array[index];
+		const oldValue = this._array[index];
 		this._array[index] = value;
 
 		this.notify(<ChangedData<T>>{
@@ -114,7 +116,7 @@ export class ObservableArray<T> extends Observable {
 
 	set length(value: number) {
 		if (types.isNumber(value) && this._array && this._array.length !== value) {
-			let added=[];
+			const added=[];
 			for (let i=this._array.length;i < value;++i) {
 				added.push(undefined);
 			}
@@ -137,9 +139,9 @@ export class ObservableArray<T> extends Observable {
 	 * Combines two or more arrays.
 	 * @param items Additional items to add to the end of array1.
 	 */
-	concat(_args?: any): T[] {
+	concat(...args): T[] {
 		this._addArgs.index = this._array.length;
-		const result = this._array.concat.apply(this._array, arguments);
+		const result = this._array.concat(...args);
 
 		return result;
 	}
@@ -182,7 +184,7 @@ export class ObservableArray<T> extends Observable {
 				this._array.push(source[i]);
 			}
 		} else {
-			this._array.push.apply(this._array, arguments);
+			this._array.push(...args);
 		}
 
 		this._addArgs.addedCount = this._array.length - this._addArgs.index;
@@ -245,7 +247,7 @@ export class ObservableArray<T> extends Observable {
 	 */
 	splice(start: number, deleteCount?: number, ...items: any): T[] {
 		const length = this._array.length;
-		const result = this._array.splice.apply(this._array, arguments);
+		const result = this._array.splice(start, deleteCount, ...items);
 
 		this.notify(<ChangedData<T>>{
 			eventName: CHANGE,
@@ -276,7 +278,7 @@ export class ObservableArray<T> extends Observable {
 	 */
 	unshift(...args: any): number {
 		const length = this._array.length;
-		const result = this._array.unshift.apply(this._array, arguments);
+		const result = this._array.unshift(...args);
 
 		this._addArgs.index = 0;
 		this._addArgs.addedCount = result - length;

packages/core/debugger/InspectorBackendCommands.ios.ts

@@ -1,5 +1,5 @@
-declare var __registerDomainDispatcher;
-declare var __inspectorSendEvent;
+declare let __registerDomainDispatcher;
+declare let __inspectorSendEvent;
 export function DomainDispatcher(domain: string): ClassDecorator {
 	return (klass) => __registerDomainDispatcher(domain, klass);
 }

packages/core/debugger/devtools-elements.common.ts

@@ -6,11 +6,13 @@ import { getNodeById } from './dom-node';
 import { mainThreadify } from '../utils';
 
 // Use lazy requires for core modules
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const getAppRootView = () => require('../application').getRootView();
 
 let unsetValue;
 function unsetViewValue(view, name) {
 	if (!unsetValue) {
+		// eslint-disable-next-line @typescript-eslint/no-var-requires
 		unsetValue = require('../ui/core/properties').unsetValue;
 	}
 
@@ -55,7 +57,7 @@ export const removeNode = mainThreadify(function removeNode(nodeId) {
 	const view = getViewById(nodeId);
 	if (view) {
 		// Avoid importing layout and content view
-		let parent = <any>view.parent;
+		const parent = <any>view.parent;
 		if (parent.removeChild) {
 			parent.removeChild(view);
 		} else if (parent.content === view) {
@@ -70,14 +72,14 @@ export const setAttributeAsText = mainThreadify(function setAttributeAsText(node
 	const view = getViewById(nodeId);
 	if (view) {
 		// attribute is registered for the view instance
-		let hasOriginalAttribute = !!name.trim();
+		const hasOriginalAttribute = !!name.trim();
 
 		if (text) {
-			let textParts = text.split('=');
+			const textParts = text.split('=');
 
 			if (textParts.length === 2) {
-				let attrName = textParts[0];
-				let attrValue = textParts[1].replace(/['"]+/g, '');
+				const attrName = textParts[0];
+				const attrValue = textParts[1].replace(/['"]+/g, '');
 
 				// if attr name is being replaced with another
 				if (name !== attrName && hasOriginalAttribute) {

packages/core/debugger/dom-node.ts

@@ -14,8 +14,11 @@ function lazy<T>(action: () => T): () => T {
 
 	return () => _value || (_value = action());
 }
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const percentLengthToStringLazy = lazy<(length) => string>(() => require('../ui/styling/style-properties').PercentLength.convertToString);
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const getSetPropertiesLazy = lazy<(view: ViewBase) => [string, any][]>(() => require('../ui/core/properties').getSetProperties);
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const getComputedCssValuesLazy = lazy<(view: ViewBase) => [string, any][]>(() => require('../ui/core/properties').getComputedCssValues);
 
 export function registerInspectorEvents(inspector: InspectorEvents) {
@@ -128,7 +131,7 @@ export class DOMNode {
 
 				return true;
 			});
-			const index = !!previousChild ? previousChild._domId : 0;
+			const index = previousChild ? previousChild._domId : 0;
 
 			childView.ensureDomNode();
 			ins.childNodeInserted(this.nodeId, index, childView.domNode);

packages/core/debugger/index.ts

@@ -208,7 +208,7 @@ export namespace NetworkAgent {
 	}
 
 	function mimeTypeToType(mimeType: string): string {
-		let type: string = 'Document';
+		let type = 'Document';
 
 		if (mimeType) {
 			if (mimeType.indexOf('image') === 0) {

packages/core/debugger/webinspector-css.ios.ts

@@ -1,4 +1,5 @@
 import * as inspectorCommandTypes from './InspectorBackendCommands.ios';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const inspectorCommands: typeof inspectorCommandTypes = require('./InspectorBackendCommands');
 
 import * as debuggerDomains from '.';

packages/core/debugger/webinspector-dom.ios.ts

@@ -1,4 +1,5 @@
 import * as inspectorCommandTypes from './InspectorBackendCommands.ios';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const inspectorCommands: typeof inspectorCommandTypes = require('./InspectorBackendCommands');
 
 import * as debuggerDomains from '.';

packages/core/debugger/webinspector-network.ios.ts

@@ -1,11 +1,12 @@
 import * as inspectorCommandTypes from './InspectorBackendCommands.ios';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const inspectorCommands: typeof inspectorCommandTypes = require('./InspectorBackendCommands');
 
 import * as debuggerDomains from '.';
 
-declare var __inspectorSendEvent;
+declare let __inspectorSendEvent;
 
-declare var __inspectorTimestamp;
+declare let __inspectorTimestamp;
 
 const frameId = 'NativeScriptMainFrameIdentifier';
 const loaderId = 'Loader Identifier';
@@ -222,11 +223,11 @@ export class NetworkDomainDebugger implements inspectorCommandTypes.NetworkDomai
 	 * Loads a resource in the context of a frame on the inspected page without cross origin checks.
 	 */
 	loadResource(params: inspectorCommandTypes.NetworkDomain.LoadResourceMethodArguments): { content: string; mimeType: string; status: number } {
-		let appPath = NSBundle.mainBundle.bundlePath;
-		let pathUrl = params.url.replace('file://', appPath);
-		let fileManager = NSFileManager.defaultManager;
-		let data = fileManager.fileExistsAtPath(pathUrl) ? fileManager.contentsAtPath(pathUrl) : undefined;
-		let content = data ? NSString.alloc().initWithDataEncoding(data, NSUTF8StringEncoding) : '';
+		const appPath = NSBundle.mainBundle.bundlePath;
+		const pathUrl = params.url.replace('file://', appPath);
+		const fileManager = NSFileManager.defaultManager;
+		const data = fileManager.fileExistsAtPath(pathUrl) ? fileManager.contentsAtPath(pathUrl) : undefined;
+		const content = data ? NSString.alloc().initWithDataEncoding(data, NSUTF8StringEncoding) : '';
 
 		return {
 			content: content.toString(), // Not sure why however we need to call toString() for NSString
@@ -235,10 +236,10 @@ export class NetworkDomainDebugger implements inspectorCommandTypes.NetworkDomai
 		};
 	}
 
-	public static idSequence: number = 0;
+	public static idSequence = 0;
 	create(): Request {
-		let id = (++NetworkDomainDebugger.idSequence).toString();
-		let resourceData = new Request(this, id);
+		const id = (++NetworkDomainDebugger.idSequence).toString();
+		const resourceData = new Request(this, id);
 		resources_datas[id] = resourceData;
 
 		return resourceData;

packages/core/file-system/file-system-access.android.ts

@@ -449,7 +449,7 @@ export class FileSystemAccess {
 		}
 
 		let childFile: java.io.File;
-		let success: boolean = false;
+		let success = false;
 
 		for (let i = 0; i < filesList.length; i++) {
 			childFile = filesList[i];

packages/core/file-system/index.ts

@@ -536,7 +536,7 @@ export class Folder extends FileSystemEntity {
 	}
 }
 
-export module knownFolders {
+export namespace knownFolders {
 	let _documents: Folder;
 	let _temp: Folder;
 	let _app: Folder;
@@ -574,7 +574,7 @@ export module knownFolders {
 		return _app;
 	}
 
-	export module ios {
+	export namespace ios {
 		function _checkPlatform(knownFolderName: string) {
 			if (!global.isIOS) {
 				throw new Error(`The "${knownFolderName}" known folder is available on iOS only!`);
@@ -585,7 +585,7 @@ export module knownFolders {
 		export function library(): Folder {
 			_checkPlatform('library');
 			if (!_library) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.LibraryDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.LibraryDirectory);
 
 				if (existingFolderInfo) {
 					_library = existingFolderInfo.folder;
@@ -601,7 +601,7 @@ export module knownFolders {
 		export function developer(): Folder {
 			_checkPlatform('developer');
 			if (!_developer) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DeveloperDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DeveloperDirectory);
 
 				if (existingFolderInfo) {
 					_developer = existingFolderInfo.folder;
@@ -617,7 +617,7 @@ export module knownFolders {
 		export function desktop(): Folder {
 			_checkPlatform('desktop');
 			if (!_desktop) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DesktopDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DesktopDirectory);
 
 				if (existingFolderInfo) {
 					_desktop = existingFolderInfo.folder;
@@ -633,7 +633,7 @@ export module knownFolders {
 		export function downloads(): Folder {
 			_checkPlatform('downloads');
 			if (!_downloads) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DownloadsDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.DownloadsDirectory);
 
 				if (existingFolderInfo) {
 					_downloads = existingFolderInfo.folder;
@@ -649,7 +649,7 @@ export module knownFolders {
 		export function movies(): Folder {
 			_checkPlatform('movies');
 			if (!_movies) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.MoviesDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.MoviesDirectory);
 
 				if (existingFolderInfo) {
 					_movies = existingFolderInfo.folder;
@@ -665,7 +665,7 @@ export module knownFolders {
 		export function music(): Folder {
 			_checkPlatform('music');
 			if (!_music) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.MusicDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.MusicDirectory);
 
 				if (existingFolderInfo) {
 					_music = existingFolderInfo.folder;
@@ -681,7 +681,7 @@ export module knownFolders {
 		export function pictures(): Folder {
 			_checkPlatform('pictures');
 			if (!_pictures) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.PicturesDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.PicturesDirectory);
 
 				if (existingFolderInfo) {
 					_pictures = existingFolderInfo.folder;
@@ -697,7 +697,7 @@ export module knownFolders {
 		export function sharedPublic(): Folder {
 			_checkPlatform('sharedPublic');
 			if (!_sharedPublic) {
-				let existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.SharedPublicDirectory);
+				const existingFolderInfo = getExistingFolderInfo(NSSearchPathDirectory.SharedPublicDirectory);
 
 				if (existingFolderInfo) {
 					_sharedPublic = existingFolderInfo.folder;
@@ -726,7 +726,7 @@ export module knownFolders {
 	}
 }
 
-export module path {
+export namespace path {
 	export function normalize(path: string): string {
 		return getFileAccess().normalizePath(path);
 	}

packages/core/fps-meter/fps-native.ios.ts

@@ -5,14 +5,14 @@ class FrameHandlerImpl extends NSObject {
 	private _owner: WeakRef<FPSCallback>;
 
 	public static initWithOwner(owner: WeakRef<FPSCallback>): FrameHandlerImpl {
-		let handler = <FrameHandlerImpl>FrameHandlerImpl.new();
+		const handler = <FrameHandlerImpl>FrameHandlerImpl.new();
 		handler._owner = owner;
 
 		return handler;
 	}
 
 	public handleFrame(sender: CADisplayLink): void {
-		let owner = this._owner.get();
+		const owner = this._owner.get();
 		if (owner) {
 			owner._handleFrame(sender);
 		}

packages/core/fps-meter/index.ts

@@ -86,7 +86,7 @@ export function removeCallback(id: number) {
 
 function notify(fps) {
 	let callback: Function;
-	for (let id in callbacks) {
+	for (const id in callbacks) {
 		callback = callbacks[id];
 		callback(fps, _minFps);
 	}

packages/core/global-types.d.ts

@@ -1,4 +1,5 @@
-declare let global: NodeJS.Global & typeof globalThis;
+/* eslint-disable no-var */
+declare var global: NodeJS.Global & typeof globalThis;
 
 interface ModuleResolver {
 	/**
@@ -253,12 +254,6 @@ declare function NativeClass<T extends { new (...args: any[]): {} }>(options?: N
  */
 declare function Interfaces(...interfaces): ClassDecorator;
 
-/**
- * Decorates class that extends native Java class
- * @param nativeClassName The name of the newly generated class. Must be unique in the application.
- */
-declare function JavaProxy(nativeClassName: string): ClassDecorator;
-
 /**
  * Important: Not applicable to Objective-C classes (iOS platform)
  * Decorates class that extends native Java class
@@ -266,6 +261,12 @@ declare function JavaProxy(nativeClassName: string): ClassDecorator;
  */
 declare function Interfaces(interfaces: any[]): ClassDecorator;
 
+/**
+ * Decorates class that extends native Java class
+ * @param nativeClassName The name of the newly generated class. Must be unique in the application.
+ */
+declare function JavaProxy(nativeClassName: string): ClassDecorator;
+
 /**
  * Important: Not applicable to Java classes (Android platform)
  * Decorates a class that implements native Objective-C protocols.

packages/core/globals/index.ts

@@ -1,4 +1,5 @@
 import * as tslibType from 'tslib';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const tslib: typeof tslibType = require('tslib');
 import { Observable } from '../data/observable';
 import { trace as profilingTrace, time, uptime, level as profilingLevel } from '../profiling';
@@ -18,10 +19,10 @@ function registerOnGlobalContext(moduleName: string, exportName: string): void {
 	Object.defineProperty(global, exportName, {
 		get: function () {
 			// We do not need to cache require() call since it is already cached in the runtime.
-			let m = global.loadModule(moduleName);
+			const m = global.loadModule(moduleName);
 
 			// Redefine the property to make sure the above code is executed only once.
-			let resolvedValue = m[exportName];
+			const resolvedValue = m[exportName];
 			Object.defineProperty(global, exportName, {
 				value: resolvedValue,
 				configurable: true,
@@ -117,7 +118,7 @@ export function initGlobal() {
 		// Required by V8 snapshot generator
 		if (!(<any>global).__extends) {
 			(<any>global).__extends = function (d, b) {
-				for (let p in b) {
+				for (const p in b) {
 					if (b.hasOwnProperty(p)) {
 						d[p] = b[p];
 					}
@@ -234,7 +235,7 @@ export function initGlobal() {
 			return modules.has(name);
 		};
 
-		global.loadModule = function loadModule(name: string, isUIModule: boolean = false): any {
+		global.loadModule = function loadModule(name: string, isUIModule = false): any {
 			const moduleInfo = modules.get(name);
 			if (moduleInfo) {
 				if (isUIModule) {
@@ -250,7 +251,7 @@ export function initGlobal() {
 				return result;
 			}
 
-			for (let resolver of (<any>global).moduleResolvers) {
+			for (const resolver of (<any>global).moduleResolvers) {
 				const result = resolver(name);
 				if (result) {
 					modules.set(name, { moduleId: name, loader: () => result });
@@ -270,7 +271,7 @@ export function initGlobal() {
 		// This method iterates all the keys in the source exports object and copies them to the destination exports one.
 		// Note: the method will not check for naming collisions and will override any already existing entries in the destination exports.
 		global.moduleMerge = function (sourceExports: any, destExports: any) {
-			for (let key in sourceExports) {
+			for (const key in sourceExports) {
 				destExports[key] = sourceExports[key];
 			}
 		};

packages/core/http/http-request/index.android.ts

@@ -191,7 +191,7 @@ function buildJavaOptions(options: httpModule.HttpRequestOptions) {
 		const arrayList = new java.util.ArrayList<org.nativescript.widgets.Async.Http.KeyValuePair>();
 		const pair = org.nativescript.widgets.Async.Http.KeyValuePair;
 
-		for (let key in options.headers) {
+		for (const key in options.headers) {
 			arrayList.add(new pair(key, options.headers[key] + ''));
 		}
 

packages/core/http/http-request/index.ios.ts

@@ -87,7 +87,7 @@ export function request(options: httpModule.HttpRequestOptions): Promise<httpMod
 			urlRequest.setValueForHTTPHeaderField(USER_AGENT, USER_AGENT_HEADER);
 
 			if (options.headers) {
-				for (let header in options.headers) {
+				for (const header in options.headers) {
 					urlRequest.setValueForHTTPHeaderField(options.headers[header] + '', header);
 				}
 			}

packages/core/image-asset/image-asset-common.ts

@@ -36,9 +36,9 @@ export class ImageAssetBase extends Observable implements ImageAssetDefinition {
 }
 
 export function getAspectSafeDimensions(sourceWidth, sourceHeight, reqWidth, reqHeight) {
-	let widthCoef = sourceWidth / reqWidth;
-	let heightCoef = sourceHeight / reqHeight;
-	let aspectCoef = Math.min(widthCoef, heightCoef);
+	const widthCoef = sourceWidth / reqWidth;
+	const heightCoef = sourceHeight / reqHeight;
+	const aspectCoef = Math.min(widthCoef, heightCoef);
 
 	return {
 		width: Math.floor(sourceWidth / aspectCoef),
@@ -51,7 +51,7 @@ export function getRequestedImageSize(src: { width: number; height: number }, op
 	let reqHeight = options.height || Math.min(src.height, Screen.mainScreen.heightPixels);
 
 	if (options && options.keepAspectRatio) {
-		let safeAspectSize = getAspectSafeDimensions(src.width, src.height, reqWidth, reqHeight);
+		const safeAspectSize = getAspectSafeDimensions(src.width, src.height, reqWidth, reqHeight);
 		reqWidth = safeAspectSize.width;
 		reqHeight = safeAspectSize.height;
 	}

packages/core/image-asset/index.android.ts

@@ -25,19 +25,19 @@ export class ImageAsset extends ImageAssetBase {
 	}
 
 	public getImageAsync(callback: (image, error) => void) {
-		let bitmapOptions = new android.graphics.BitmapFactory.Options();
+		const bitmapOptions = new android.graphics.BitmapFactory.Options();
 		bitmapOptions.inJustDecodeBounds = true;
 		// read only the file size
 		let bitmap = android.graphics.BitmapFactory.decodeFile(this.android, bitmapOptions);
-		let sourceSize = {
+		const sourceSize = {
 			width: bitmapOptions.outWidth,
 			height: bitmapOptions.outHeight,
 		};
-		let requestedSize = getRequestedImageSize(sourceSize, this.options);
+		const requestedSize = getRequestedImageSize(sourceSize, this.options);
 
-		let sampleSize = org.nativescript.widgets.image.Fetcher.calculateInSampleSize(bitmapOptions.outWidth, bitmapOptions.outHeight, requestedSize.width, requestedSize.height);
+		const sampleSize = org.nativescript.widgets.image.Fetcher.calculateInSampleSize(bitmapOptions.outWidth, bitmapOptions.outHeight, requestedSize.width, requestedSize.height);
 
-		let finalBitmapOptions = new android.graphics.BitmapFactory.Options();
+		const finalBitmapOptions = new android.graphics.BitmapFactory.Options();
 		finalBitmapOptions.inSampleSize = sampleSize;
 		try {
 			let error = null;

packages/core/image-asset/index.ios.ts

@@ -35,25 +35,25 @@ export class ImageAsset extends ImageAssetBase {
 			callback(null, 'Asset cannot be found.');
 		}
 
-		let srcWidth = this.nativeImage ? this.nativeImage.size.width : this.ios.pixelWidth;
-		let srcHeight = this.nativeImage ? this.nativeImage.size.height : this.ios.pixelHeight;
-		let requestedSize = getRequestedImageSize({ width: srcWidth, height: srcHeight }, this.options);
+		const srcWidth = this.nativeImage ? this.nativeImage.size.width : this.ios.pixelWidth;
+		const srcHeight = this.nativeImage ? this.nativeImage.size.height : this.ios.pixelHeight;
+		const requestedSize = getRequestedImageSize({ width: srcWidth, height: srcHeight }, this.options);
 
 		if (this.nativeImage) {
-			let newSize = CGSizeMake(requestedSize.width, requestedSize.height);
-			let resizedImage = this.scaleImage(this.nativeImage, newSize);
+			const newSize = CGSizeMake(requestedSize.width, requestedSize.height);
+			const resizedImage = this.scaleImage(this.nativeImage, newSize);
 			callback(resizedImage, null);
 
 			return;
 		}
 
-		let imageRequestOptions = PHImageRequestOptions.alloc().init();
+		const imageRequestOptions = PHImageRequestOptions.alloc().init();
 		imageRequestOptions.deliveryMode = PHImageRequestOptionsDeliveryMode.HighQualityFormat;
 		imageRequestOptions.networkAccessAllowed = true;
 
 		PHImageManager.defaultManager().requestImageForAssetTargetSizeContentModeOptionsResultHandler(this.ios, requestedSize, PHImageContentMode.AspectFit, imageRequestOptions, (image, imageResultInfo) => {
 			if (image) {
-				let resultImage = this.scaleImage(image, requestedSize);
+				const resultImage = this.scaleImage(image, requestedSize);
 				callback(resultImage, null);
 			} else {
 				callback(null, imageResultInfo.valueForKey(PHImageErrorKey));
@@ -67,7 +67,7 @@ export class ImageAsset extends ImageAssetBase {
 
 		UIGraphicsBeginImageContextWithOptions(requestedSize, false, scaleFactor);
 		image.drawInRect(CGRectMake(0, 0, requestedSize.width, requestedSize.height));
-		let resultImage = UIGraphicsGetImageFromCurrentImageContext();
+		const resultImage = UIGraphicsGetImageFromCurrentImageContext();
 		UIGraphicsEndImageContext();
 
 		return resultImage;

packages/core/index.ts

@@ -110,7 +110,7 @@ export * from './trace';
 
 export * from './ui';
 
-import { GC, isFontIconURI, isDataURI, isFileOrResourcePath, executeOnMainThread, mainThreadify, isMainThread, dispatchToMainThread, releaseNativeObject, getModuleName, openFile, openUrl, isRealDevice, layout, ad as androidUtils, iOSNativeHelper as iosUtils, Source, RESOURCE_PREFIX, FILE_PREFIX } from './utils';
+import { GC, isFontIconURI, isDataURI, isFileOrResourcePath, executeOnMainThread, mainThreadify, isMainThread, dispatchToMainThread, queueMacrotask, releaseNativeObject, getModuleName, openFile, openUrl, isRealDevice, layout, ad as androidUtils, iOSNativeHelper as iosUtils, Source, RESOURCE_PREFIX, FILE_PREFIX } from './utils';
 import { ClassInfo, getClass, getBaseClasses, getClassInfo, isBoolean, isDefined, isFunction, isNullOrUndefined, isNumber, isObject, isString, isUndefined, toUIString, verifyCallback } from './utils/types';
 
 export const Utils = {
@@ -124,6 +124,7 @@ export const Utils = {
 	mainThreadify,
 	isMainThread,
 	dispatchToMainThread,
+	queueMacrotask,
 	releaseNativeObject,
 
 	getModuleName,

packages/core/js-libs/esprima/esprima.d.ts

@@ -25,7 +25,7 @@ export interface Options {
     source?: boolean
 }
 
-export module Syntax {
+export namespace Syntax {
     // Node
     interface Node {
         type: string
@@ -69,10 +69,8 @@ export module Syntax {
     }
 
     // Statement
-    interface Statement extends Node {
-    }
-    interface EmptyStatement extends Statement {
-    }
+    type Statement = Node
+    type EmptyStatement = Statement
     interface BlockStatement extends Statement {
         body: SomeStatement[]
     }
@@ -137,8 +135,7 @@ export module Syntax {
     }
     interface VariableDeclaratorOrExpression extends VariableDeclarator, SomeExpression {
     }
-    interface DebuggerStatement extends Statement {
-    }
+    type DebuggerStatement = Statement
     interface SomeStatement extends
         EmptyStatement, ExpressionStatement, BlockStatement, IfStatement,
         LabeledStatement, BreakStatement, ContinueStatement, WithStatement,
@@ -150,8 +147,7 @@ export module Syntax {
     }
 
     // Declration
-    interface Declration extends Statement {
-    }
+    type Declration = Statement
     interface FunctionDeclration extends Declration {
         id: Identifier
         params: Identifier[] // Pattern
@@ -171,16 +167,14 @@ export module Syntax {
     }
 
     // Expression
-    interface Expression extends Node { // | Pattern
-    }
+    type Expression = Node
     interface SomeExpression extends
         ThisExpression, ArrayExpression, ObjectExpression, FunctionExpression,
         ArrowFunctionExpression, SequenceExpression, UnaryExpression, BinaryExpression,
         AssignmentExpression, UpdateExpression, LogicalExpression, ConditionalExpression,
         NewExpression, CallExpression, MemberExpression {
     }
-    interface ThisExpression extends Expression {
-    }
+    type ThisExpression = Expression
     interface ArrayExpression extends Expression {
         elements: SomeExpression[] // [ Expression | null ]
     }

packages/core/module-name-resolver/index.ts

@@ -39,7 +39,7 @@ export class ModuleNameResolver {
 		// This call will return a clean path without qualifiers
 		path = stripQualifiers(path);
 
-		let candidates = this.getCandidates(path, ext);
+		const candidates = this.getCandidates(path, ext);
 		result = findMatch(path, ext, candidates, this.context);
 
 		return result;

packages/core/module-name-resolver/non-bundle-workflow-compat.ts

@@ -25,7 +25,7 @@ function processFile(file: fs.File) {
 	const loadContent = () => file.readTextSync();
 
 	switch (file.extension.toLocaleLowerCase()) {
-		case '.js':
+		case '.js':{
 			const noExtPath = filePathRelativeToApp.substr(0, filePathRelativeToApp.length - '.js'.length);
 
 			register(filePathRelativeToApp, function () {
@@ -35,6 +35,7 @@ function processFile(file: fs.File) {
 				return global.require(file.path);
 			});
 			break;
+		}
 
 		case '.css':
 			register(filePathRelativeToApp, loadContent);
@@ -48,8 +49,8 @@ function processFile(file: fs.File) {
 	if (file.name === 'package.json') {
 		const json = global.require(file.path);
 		if (json.main) {
-			let name = filePathRelativeToApp.substr(0, filePathRelativeToApp.length - 'package.json'.length - 1);
-			let requirePath = fs.path.join(file.parent.path, json.main);
+			const name = filePathRelativeToApp.substr(0, filePathRelativeToApp.length - 'package.json'.length - 1);
+			const requirePath = fs.path.join(file.parent.path, json.main);
 
 			register(name, () => global.require(requirePath));
 		}

packages/core/module-name-resolver/qualifier-matcher/index.ts

@@ -1,6 +1,6 @@
-const MIN_WH: string = 'minWH';
-const MIN_W: string = 'minW';
-const MIN_H: string = 'minH';
+const MIN_WH = 'minWH';
+const MIN_W = 'minW';
+const MIN_H = 'minH';
 const PRIORITY_STEP = 10000;
 
 /**
@@ -120,9 +120,9 @@ const supportedQualifiers: Array<QualifierSpec> = [minWidthHeightQualifier, minW
 function checkQualifiers(path: string, context: PlatformContext): number {
 	let result = 0;
 	for (let i = 0; i < supportedQualifiers.length; i++) {
-		let qualifier = supportedQualifiers[i];
+		const qualifier = supportedQualifiers[i];
 		if (qualifier.isMatch(path)) {
-			let occurences = qualifier.getMatchOccurences(path);
+			const occurences = qualifier.getMatchOccurences(path);
 			// Always get the last qualifier among identical occurences
 			result = qualifier.getMatchValue(occurences[occurences.length - 1], context);
 			if (result < 0) {
@@ -142,9 +142,9 @@ function checkQualifiers(path: string, context: PlatformContext): number {
 export function stripQualifiers(path: string): string {
 	// Strip qualifiers from path if any
 	for (let i = 0; i < supportedQualifiers.length; i++) {
-		let qualifier = supportedQualifiers[i];
+		const qualifier = supportedQualifiers[i];
 		if (qualifier.isMatch(path)) {
-			let occurences = qualifier.getMatchOccurences(path);
+			const occurences = qualifier.getMatchOccurences(path);
 			for (let j = 0; j < occurences.length; j++) {
 				path = path.replace(occurences[j], '');
 			}
@@ -155,7 +155,7 @@ export function stripQualifiers(path: string): string {
 }
 
 export function findMatch(path: string, ext: string, candidates: Array<string>, context: PlatformContext): string {
-	let fullPath: string = ext ? path + ext : path;
+	const fullPath: string = ext ? path + ext : path;
 	let bestValue = -1;
 	let result: string = null;
 

packages/core/platform/index.android.ts

@@ -1,5 +1,5 @@
 /* tslint:disable:class-name */
-import { getNativeApplication, on, off, orientationChangedEvent, android as AndroidApplication } from '../application';
+import { getNativeApplication, on, orientationChangedEvent, android as AndroidApplication } from '../application';
 
 const MIN_TABLET_PIXELS = 600;
 

packages/core/platforms/ios/typings/objc!MaterialComponents.d.ts

@@ -227,51 +227,51 @@ declare var MDCInkViewDelegate: {
 	prototype: MDCInkViewDelegate;
 };
 
-declare var MDCShadowElevationAppBar: number;
+declare let MDCShadowElevationAppBar: number;
 
-declare var MDCShadowElevationBottomNavigationBar: number;
+declare let MDCShadowElevationBottomNavigationBar: number;
 
-declare var MDCShadowElevationCardPickedUp: number;
+declare let MDCShadowElevationCardPickedUp: number;
 
-declare var MDCShadowElevationCardResting: number;
+declare let MDCShadowElevationCardResting: number;
 
-declare var MDCShadowElevationDialog: number;
+declare let MDCShadowElevationDialog: number;
 
-declare var MDCShadowElevationFABPressed: number;
+declare let MDCShadowElevationFABPressed: number;
 
-declare var MDCShadowElevationFABResting: number;
+declare let MDCShadowElevationFABResting: number;
 
-declare var MDCShadowElevationMenu: number;
+declare let MDCShadowElevationMenu: number;
 
-declare var MDCShadowElevationModalBottomSheet: number;
+declare let MDCShadowElevationModalBottomSheet: number;
 
-declare var MDCShadowElevationNavDrawer: number;
+declare let MDCShadowElevationNavDrawer: number;
 
-declare var MDCShadowElevationNone: number;
+declare let MDCShadowElevationNone: number;
 
-declare var MDCShadowElevationPicker: number;
+declare let MDCShadowElevationPicker: number;
 
-declare var MDCShadowElevationQuickEntry: number;
+declare let MDCShadowElevationQuickEntry: number;
 
-declare var MDCShadowElevationQuickEntryResting: number;
+declare let MDCShadowElevationQuickEntryResting: number;
 
-declare var MDCShadowElevationRaisedButtonPressed: number;
+declare let MDCShadowElevationRaisedButtonPressed: number;
 
-declare var MDCShadowElevationRaisedButtonResting: number;
+declare let MDCShadowElevationRaisedButtonResting: number;
 
-declare var MDCShadowElevationRefresh: number;
+declare let MDCShadowElevationRefresh: number;
 
-declare var MDCShadowElevationRightDrawer: number;
+declare let MDCShadowElevationRightDrawer: number;
 
-declare var MDCShadowElevationSearchBarResting: number;
+declare let MDCShadowElevationSearchBarResting: number;
 
-declare var MDCShadowElevationSearchBarScrolled: number;
+declare let MDCShadowElevationSearchBarScrolled: number;
 
-declare var MDCShadowElevationSnackbar: number;
+declare let MDCShadowElevationSnackbar: number;
 
-declare var MDCShadowElevationSubMenu: number;
+declare let MDCShadowElevationSubMenu: number;
 
-declare var MDCShadowElevationSwitch: number;
+declare let MDCShadowElevationSwitch: number;
 
 declare class MDCShadowLayer extends CALayer implements CALayerDelegate {
 
@@ -716,7 +716,7 @@ declare class MDCTabBarViewController extends UIViewController implements MDCTab
 	tabBarWillSelectItem(tabBar: MDCTabBar, item: UITabBarItem): void;
 }
 
-declare var MDCTabBarViewControllerAnimationDuration: number;
+declare let MDCTabBarViewControllerAnimationDuration: number;
 
 declare class MDCTypography extends NSObject {
 
@@ -804,6 +804,6 @@ declare var MDCTypographyFontLoading: {
 	prototype: MDCTypographyFontLoading;
 };
 
-declare var MaterialComponentsVersionNumber: number;
+declare let MaterialComponentsVersionNumber: number;
 
-declare var MaterialComponentsVersionString: interop.Reference<number>;
+declare let MaterialComponentsVersionString: interop.Reference<number>;

packages/core/profiling/index.ts

@@ -1,5 +1,5 @@
-declare var __startCPUProfiler: any;
-declare var __stopCPUProfiler: any;
+declare let __startCPUProfiler: any;
+declare let __stopCPUProfiler: any;
 
 export function uptime() {
 	return global.android ? (<any>org).nativescript.Process.getUpTime() : (<any>global).__tns_uptime();
@@ -98,10 +98,10 @@ export function isRunning(name: string): boolean {
 function countersProfileFunctionFactory<F extends Function>(fn: F, name: string, type: MemberType = MemberType.Instance): F {
 	profileNames.push(name);
 
-	return <any>function () {
+	return <any>function (...args) {
 		start(name);
 		try {
-			return fn.apply(this, arguments);
+			return fn(...args);
 		} finally {
 			stop(name);
 		}
@@ -110,19 +110,19 @@ function countersProfileFunctionFactory<F extends Function>(fn: F, name: string,
 
 function timelineProfileFunctionFactory<F extends Function>(fn: F, name: string, type: MemberType = MemberType.Instance): F {
 	return type === MemberType.Instance
-		? <any>function () {
+		? <any>function (...args) {
 				const start = time();
 				try {
-					return fn.apply(this, arguments);
+					return fn(...args);
 				} finally {
 					const end = time();
 					console.log(`Timeline: Modules: ${name} ${this}  (${start}ms. - ${end}ms.)`);
 				}
 		  }
-		: function () {
+		: function (...args) {
 				const start = time();
 				try {
-					return fn.apply(this, arguments);
+					return fn(...args);
 				} finally {
 					const end = time();
 					console.log(`Timeline: Modules: ${name}  (${start}ms. - ${end}ms.)`);
@@ -159,6 +159,7 @@ export function enable(mode: InstrumentationMode = 'counters') {
 }
 
 try {
+	// eslint-disable-next-line @typescript-eslint/no-var-requires
 	const appConfig = require('~/package.json');
 	if (appConfig && appConfig.profiling) {
 		enable(appConfig.profiling);
@@ -192,7 +193,7 @@ const profileMethodUnnamed = (target, key, descriptor) => {
 		className = target.constructor.name + '.';
 	}
 
-	let name = className + key;
+	const name = className + key;
 
 	//editing the descriptor/value parameter
 	descriptor.value = profileFunctionFactory(originalMethod, name, MemberType.Instance);
@@ -213,7 +214,7 @@ const profileStaticMethodUnnamed = (ctor, key, descriptor) => {
 	if (ctor && ctor.name) {
 		className = ctor.name + '.';
 	}
-	let name = className + key;
+	const name = className + key;
 
 	//editing the descriptor/value parameter
 	descriptor.value = profileFunctionFactory(originalMethod, name, MemberType.Static);

packages/core/text/index.android.ts

@@ -1,6 +1,6 @@
 export * from './text-common';
 
-export module encoding {
+export namespace encoding {
 	export const ISO_8859_1 = 'ISO-8859-1';
 	export const US_ASCII = 'US-ASCII';
 	export const UTF_16 = 'UTF-16';

packages/core/text/index.d.ts

@@ -3,7 +3,7 @@
 /**
  * Defines the supported character encodings.
  */
-export module encoding {
+export namespace encoding {
 	/**
 	 * Denotes ISO-8859-1 character encoding.
 	 */

packages/core/text/index.ios.ts

@@ -1,6 +1,6 @@
 export * from './text-common';
 
-export module encoding {
+export namespace encoding {
 	export const ISO_8859_1 = 5; //NSISOLatin1StringEncoding
 	export const US_ASCII = 1; //NSASCIIStringEncoding
 	export const UTF_16 = 10; //NSUnicodeStringEncoding

packages/core/text/text-common.ts

@@ -2,11 +2,11 @@ const Object_prototype_toString = {}.toString;
 const ArrayBufferString = Object_prototype_toString.call(ArrayBuffer.prototype);
 
 function decoderReplacer(encoded) {
-	var codePoint = encoded.charCodeAt(0) << 24;
-	var leadingOnes = Math.clz32(~codePoint) | 0;
-	var endPos = 0,
-		stringLen = encoded.length | 0;
-	var result = '';
+	let codePoint = encoded.charCodeAt(0) << 24;
+	const leadingOnes = Math.clz32(~codePoint) | 0;
+	let endPos = 0;
+	const stringLen = encoded.length | 0;
+	let result = '';
 	if (leadingOnes < 5 && stringLen >= leadingOnes) {
 		codePoint = (codePoint << leadingOnes) >>> (24 + leadingOnes);
 		for (endPos = 1; endPos < leadingOnes; endPos = (endPos + 1) | 0) {
@@ -35,9 +35,9 @@ function decoderReplacer(encoded) {
 
 function encoderReplacer(nonAsciiChars) {
 	// make the UTF string into a binary UTF-8 encoded string
-	var point = nonAsciiChars.charCodeAt(0) | 0;
+	let point = nonAsciiChars.charCodeAt(0) | 0;
 	if (point >= 0xd800 && point <= 0xdbff) {
-		var nextcode = nonAsciiChars.charCodeAt(1) | 0;
+		const nextcode = nonAsciiChars.charCodeAt(1) | 0;
 		if (nextcode !== nextcode) {
 			// NaN because string is 1 code point long
 			return String.fromCharCode(0xef /*11101111*/, 0xbf /*10111111*/, 0xbd /*10111101*/);
@@ -71,7 +71,7 @@ export class TextDecoder {
 		if (Object_prototype_toString.call(buffer) !== ArrayBufferString) {
 			throw Error("Failed to execute 'decode' on 'TextDecoder': The provided value is not of type '(ArrayBuffer or ArrayBufferView)'");
 		}
-		let inputAs8 = new Uint8Array(buffer);
+		const inputAs8 = new Uint8Array(buffer);
 		let resultingString = '';
 		for (let index = 0, len = inputAs8.length | 0; index < len; index = (index + 32768) | 0) {
 			resultingString += String.fromCharCode.apply(0, inputAs8.slice(index, (index + 32768) | 0));
@@ -92,7 +92,7 @@ export class TextEncoder {
 		return 'utf-8';
 	}
 
-	public encode(input: string = ''): Uint8Array {
+	public encode(input = ''): Uint8Array {
 		// 0xc0 => 0b11000000; 0xff => 0b11111111; 0xc0-0xff => 0b11xxxxxx
 		// 0x80 => 0b10000000; 0xbf => 0b10111111; 0x80-0xbf => 0b10xxxxxx
 		const encodedString = input === undefined ? '' : ('' + input).replace(/[\x80-\uD7ff\uDC00-\uFFFF]|[\uD800-\uDBFF][\uDC00-\uDFFF]?/g, encoderReplacer);

packages/core/timer/index.android.ts

@@ -43,7 +43,7 @@ export function setTimeout(callback: Function, milliseconds = 0, ...args): numbe
 }
 
 export function clearTimeout(id: number): void {
-	let index = id;
+	const index = id;
 	if (timeoutCallbacks[index]) {
 		timeoutHandler.removeCallbacks(timeoutCallbacks[index]);
 		delete timeoutCallbacks[index];

packages/core/timer/index.ios.ts

@@ -15,7 +15,7 @@ class TimerTargetImpl extends NSObject {
 	private shouldRepeat: boolean;
 
 	public static initWithCallback(callback: Function, id: number, shouldRepeat: boolean): TimerTargetImpl {
-		let handler = <TimerTargetImpl>TimerTargetImpl.new();
+		const handler = <TimerTargetImpl>TimerTargetImpl.new();
 		handler.callback = callback;
 		handler.id = id;
 		handler.shouldRepeat = shouldRepeat;
@@ -37,7 +37,7 @@ class TimerTargetImpl extends NSObject {
 		if (!this.disposed) {
 			this.disposed = true;
 
-			let timer = timeoutCallbacks.get(this.id).k;
+			const timer = timeoutCallbacks.get(this.id).k;
 			timer.invalidate();
 			timeoutCallbacks.delete(this.id);
 		}
@@ -53,14 +53,14 @@ function createTimerAndGetId(callback: Function, milliseconds: number, shouldRep
 	milliseconds += 0;
 
 	timerId++;
-	let id = timerId;
-	let timerTarget = TimerTargetImpl.initWithCallback(callback, id, shouldRepeat);
-	let timer = NSTimer.scheduledTimerWithTimeIntervalTargetSelectorUserInfoRepeats(milliseconds / 1000, timerTarget, 'tick', null, shouldRepeat);
+	const id = timerId;
+	const timerTarget = TimerTargetImpl.initWithCallback(callback, id, shouldRepeat);
+	const timer = NSTimer.scheduledTimerWithTimeIntervalTargetSelectorUserInfoRepeats(milliseconds / 1000, timerTarget, 'tick', null, shouldRepeat);
 
 	// https://github.com/NativeScript/NativeScript/issues/2116
 	NSRunLoop.currentRunLoop.addTimerForMode(timer, NSRunLoopCommonModes);
 
-	let pair: KeyValuePair<NSTimer, TimerTargetImpl> = {
+	const pair: KeyValuePair<NSTimer, TimerTargetImpl> = {
 		k: timer,
 		v: timerTarget,
 	};
@@ -70,20 +70,20 @@ function createTimerAndGetId(callback: Function, milliseconds: number, shouldRep
 }
 
 export function setTimeout(callback: Function, milliseconds = 0, ...args): number {
-	let invoke = () => callback(...args);
+	const invoke = () => callback(...args);
 
 	return createTimerAndGetId(zonedCallback(invoke), milliseconds, false);
 }
 
 export function clearTimeout(id: number): void {
-	let pair = timeoutCallbacks.get(<number>(<any>id));
+	const pair = timeoutCallbacks.get(<number>(<any>id));
 	if (pair) {
 		pair.v.unregister();
 	}
 }
 
 export function setInterval(callback: Function, milliseconds = 0, ...args): number {
-	let invoke = () => callback(...args);
+	const invoke = () => callback(...args);
 
 	return createTimerAndGetId(zonedCallback(invoke), milliseconds, true);
 }

packages/core/trace/index.ts

@@ -22,8 +22,8 @@ export interface TraceErrorHandler {
 
 let enabled = false;
 let _categories = {};
-let _writers: Array<TraceWriter> = [];
-let _eventListeners: Array<TraceEventListener> = [];
+const _writers: Array<TraceWriter> = [];
+const _eventListeners: Array<TraceEventListener> = [];
 let _errorHandler: TraceErrorHandler;
 
 export namespace Trace {
@@ -63,7 +63,7 @@ export namespace Trace {
 	 * @param writer The TraceWriter instance to remove.
 	 */
 	export function removeWriter(writer: TraceWriter) {
-		let index = _writers.indexOf(writer);
+		const index = _writers.indexOf(writer);
 		if (index >= 0) {
 			_writers.splice(index, 1);
 		}
@@ -92,7 +92,7 @@ export namespace Trace {
 	 * @param categories The comma-separated list of categories. If not specified all messages from all categories will be traced.
 	 */
 	export function addCategories(categories: string) {
-		let split = categories.split(',');
+		const split = categories.split(',');
 		for (let i = 0; i < split.length; i++) {
 			_categories[split[i].trim()] = true;
 		}
@@ -174,7 +174,7 @@ export namespace Trace {
 		}
 	}
 
-	export module messageType {
+	export namespace messageType {
 		export const log = 0;
 		export const info = 1;
 		export const warn = 2;
@@ -184,7 +184,7 @@ export namespace Trace {
 	/**
 	 * all predefined categories.
 	 */
-	export module categories {
+	export namespace categories {
 		export const VisualTreeEvents = 'VisualTreeEvents';
 		export const Layout = 'Layout';
 		export const Style = 'Style';
@@ -206,13 +206,13 @@ export namespace Trace {
 
 		export function concat(...args: any): string {
 			let result: string;
-			for (let i = 0; i < arguments.length; i++) {
+			for (let i = 0; i < args.length; i++) {
 				if (!result) {
-					result = arguments[i];
+					result = args[i];
 					continue;
 				}
 
-				result = result.concat(separator, arguments[i]);
+				result = result.concat(separator, args[i]);
 			}
 
 			return result;

packages/core/ui/action-bar/action-bar-common.ts

@@ -365,7 +365,7 @@ export function traceMissingIcon(icon: string) {
 
 function convertToContentInset(this: void, value: string | Length): [CssProperty<any, any>, any][] {
 	if (typeof value === 'string' && value !== 'auto') {
-		let insets = value.split(/[ ,]+/);
+		const insets = value.split(/[ ,]+/);
 
 		return [
 			[androidContentInsetLeftProperty, Length.parse(insets[0])],

packages/core/ui/action-bar/index.android.ts

@@ -72,7 +72,7 @@ function initializeMenuItemClickListener(): void {
 		}
 
 		onMenuItemClick(item: android.view.MenuItem): boolean {
-			let itemId = item.getItemId();
+			const itemId = item.getItemId();
 
 			return this.owner._onAndroidItemSelected(itemId);
 		}
@@ -225,7 +225,7 @@ export class ActionBar extends ActionBarBase {
 
 		// Find item with the right ID;
 		let menuItem: ActionItem = undefined;
-		let items = this.actionItems.getItems();
+		const items = this.actionItems.getItems();
 		for (let i = 0; i < items.length; i++) {
 			if ((<ActionItem>items[i])._getItemId() === itemId) {
 				menuItem = <ActionItem>items[i];
@@ -262,11 +262,11 @@ export class ActionBar extends ActionBarBase {
 			// Set navigation content description, used by screen readers for the vision-impaired users
 			this.nativeViewProtected.setNavigationContentDescription(navButton.text || null);
 
-			let navBtn = new WeakRef(navButton);
+			const navBtn = new WeakRef(navButton);
 			this.nativeViewProtected.setNavigationOnClickListener(
 				new android.view.View.OnClickListener({
 					onClick: function (v) {
-						let owner = navBtn.get();
+						const owner = navBtn.get();
 						if (owner) {
 							owner._raiseTap();
 						}
@@ -279,18 +279,18 @@ export class ActionBar extends ActionBarBase {
 	}
 
 	public _updateIcon() {
-		let visibility = getIconVisibility(this.android.iconVisibility);
+		const visibility = getIconVisibility(this.android.iconVisibility);
 		if (visibility) {
-			let icon = this.android.icon;
+			const icon = this.android.icon;
 			if (icon !== undefined) {
-				let drawableOrId = getDrawableOrResourceId(icon, appResources);
+				const drawableOrId = getDrawableOrResourceId(icon, appResources);
 				if (drawableOrId) {
 					this.nativeViewProtected.setLogo(drawableOrId);
 				} else {
 					traceMissingIcon(icon);
 				}
 			} else {
-				let defaultIcon = application.android.nativeApp.getApplicationInfo().icon;
+				const defaultIcon = application.android.nativeApp.getApplicationInfo().icon;
 				this.nativeViewProtected.setLogo(defaultIcon);
 			}
 		} else {
@@ -301,13 +301,13 @@ export class ActionBar extends ActionBarBase {
 	public _updateTitleAndTitleView() {
 		if (!this.titleView) {
 			// No title view - show the title
-			let title = this.title;
+			const title = this.title;
 			if (title !== undefined) {
 				this.nativeViewProtected.setTitle(title);
 			} else {
-				let appContext = application.android.context;
-				let appInfo = appContext.getApplicationInfo();
-				let appLabel = appContext.getPackageManager().getApplicationLabel(appInfo);
+				const appContext = application.android.context;
+				const appInfo = appContext.getApplicationInfo();
+				const appLabel = appContext.getPackageManager().getApplicationLabel(appInfo);
 				if (appLabel) {
 					this.nativeViewProtected.setTitle(appLabel);
 				}
@@ -316,13 +316,13 @@ export class ActionBar extends ActionBarBase {
 	}
 
 	public _addActionItems() {
-		let menu = this.nativeViewProtected.getMenu();
-		let items = this.actionItems.getVisibleItems();
+		const menu = this.nativeViewProtected.getMenu();
+		const items = this.actionItems.getVisibleItems();
 
 		menu.clear();
 		for (let i = 0; i < items.length; i++) {
-			let item = <ActionItem>items[i];
-			let menuItem = menu.add(android.view.Menu.NONE, item._getItemId(), android.view.Menu.NONE, item.text + '');
+			const item = <ActionItem>items[i];
+			const menuItem = menu.add(android.view.Menu.NONE, item._getItemId(), android.view.Menu.NONE, item.text + '');
 
 			if (item.actionView && item.actionView.android) {
 				// With custom action view, the menuitem cannot be displayed in a popup menu.
@@ -331,7 +331,7 @@ export class ActionBar extends ActionBarBase {
 				ActionBar._setOnClickListener(item);
 			} else if (item.android.systemIcon) {
 				// Try to look in the system resources.
-				let systemResourceId = getSystemResourceId(item.android.systemIcon);
+				const systemResourceId = getSystemResourceId(item.android.systemIcon);
 				if (systemResourceId) {
 					menuItem.setIcon(systemResourceId);
 				}
@@ -342,7 +342,7 @@ export class ActionBar extends ActionBarBase {
 				}
 			}
 
-			let showAsAction = getShowAsAction(item);
+			const showAsAction = getShowAsAction(item);
 			menuItem.setShowAsAction(showAsAction);
 		}
 	}
@@ -471,13 +471,13 @@ function getDrawableOrResourceId(icon: string, resources: android.content.res.Re
 
 	let result = null;
 	if (icon.indexOf(RESOURCE_PREFIX) === 0) {
-		let resourceId: number = resources.getIdentifier(icon.substr(RESOURCE_PREFIX.length), 'drawable', application.android.packageName);
+		const resourceId: number = resources.getIdentifier(icon.substr(RESOURCE_PREFIX.length), 'drawable', application.android.packageName);
 		if (resourceId > 0) {
 			result = resourceId;
 		}
 	} else {
 		let drawable: android.graphics.drawable.BitmapDrawable;
-		let is = ImageSource.fromFileOrResourceSync(icon);
+		const is = ImageSource.fromFileOrResourceSync(icon);
 		if (is) {
 			drawable = new android.graphics.drawable.BitmapDrawable(appResources, is.android);
 		}

packages/core/ui/action-bar/index.ios.ts

@@ -40,14 +40,14 @@ class TapBarItemHandlerImpl extends NSObject {
 	private _owner: WeakRef<ActionItemDefinition>;
 
 	public static initWithOwner(owner: WeakRef<ActionItemDefinition>): TapBarItemHandlerImpl {
-		let handler = <TapBarItemHandlerImpl>TapBarItemHandlerImpl.new();
+		const handler = <TapBarItemHandlerImpl>TapBarItemHandlerImpl.new();
 		handler._owner = owner;
 
 		return handler;
 	}
 
 	public tap(args) {
-		let owner = this._owner.get();
+		const owner = this._owner.get();
 		if (owner) {
 			owner._raiseTap();
 		}
@@ -184,8 +184,8 @@ export class ActionBar extends ActionBarBase {
 		// Set back button text
 		if (previousController) {
 			if (this.navigationButton) {
-				let tapHandler = TapBarItemHandlerImpl.initWithOwner(new WeakRef(this.navigationButton));
-				let barButtonItem = UIBarButtonItem.alloc().initWithTitleStyleTargetAction(this.navigationButton.text + '', UIBarButtonItemStyle.Plain, tapHandler, 'tap');
+				const tapHandler = TapBarItemHandlerImpl.initWithOwner(new WeakRef(this.navigationButton));
+				const barButtonItem = UIBarButtonItem.alloc().initWithTitleStyleTargetAction(this.navigationButton.text + '', UIBarButtonItemStyle.Plain, tapHandler, 'tap');
 				previousController.navigationItem.backBarButtonItem = barButtonItem;
 			} else {
 				previousController.navigationItem.backBarButtonItem = null;
@@ -202,7 +202,7 @@ export class ActionBar extends ActionBarBase {
 		// show the one from the old page but the new page will still be visible (because we canceled EdgeBackSwipe gesutre)
 		// Consider moving this to new method and call it from - navigationControllerDidShowViewControllerAnimated.
 		if (img) {
-			let image = img.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
+			const image = img.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal);
 			navigationBar.backIndicatorImage = image;
 			navigationBar.backIndicatorTransitionMaskImage = image;
 		} else {
@@ -257,7 +257,7 @@ export class ActionBar extends ActionBarBase {
 
 		let barButtonItem: UIBarButtonItem;
 		if (item.actionView && item.actionView.ios) {
-			let recognizer = UITapGestureRecognizer.alloc().initWithTargetAction(tapHandler, 'tap');
+			const recognizer = UITapGestureRecognizer.alloc().initWithTargetAction(tapHandler, 'tap');
 			item.actionView.ios.addGestureRecognizer(recognizer);
 			barButtonItem = UIBarButtonItem.alloc().initWithCustomView(item.actionView.ios);
 		} else if (item.ios.systemIcon !== undefined) {
@@ -320,7 +320,7 @@ export class ActionBar extends ActionBarBase {
 			page.frame._updateActionBar();
 		}
 
-		let navigationItem: UINavigationItem = (<UIViewController>page.ios).navigationItem;
+		const navigationItem: UINavigationItem = (<UIViewController>page.ios).navigationItem;
 		navigationItem.title = this.title;
 	}
 
@@ -408,9 +408,9 @@ export class ActionBar extends ActionBarBase {
 		return null;
 	}
 	[backgroundColorProperty.setNative](value: UIColor | Color) {
-		let navBar = this.navBar;
+		const navBar = this.navBar;
 		if (navBar) {
-			let color = value instanceof Color ? value.ios : value;
+			const color = value instanceof Color ? value.ios : value;
 			navBar.barTintColor = color;
 		}
 	}

packages/core/ui/activity-indicator/index.ios.ts

@@ -33,7 +33,7 @@ export class ActivityIndicator extends ActivityIndicatorBase {
 		}
 	}
 	[busyProperty.setNative](value: boolean) {
-		let nativeView = this.nativeViewProtected;
+		const nativeView = this.nativeViewProtected;
 		if (value) {
 			nativeView.startAnimating();
 		} else {

packages/core/ui/animation/animation-common.ts

@@ -9,7 +9,7 @@ import { PercentLength } from '../styling/style-properties';
 
 export * from './animation-interfaces';
 
-export module Properties {
+export namespace Properties {
 	export const opacity = 'opacity';
 	export const backgroundColor = 'backgroundColor';
 	export const translate = 'translate';
@@ -100,15 +100,15 @@ export abstract class AnimationBase implements AnimationBaseDefinition {
 			_this.cancel();
 		};
 		const _then = promise.then;
-		promise.then = function () {
-			const r = _then.apply(promise, arguments);
+		promise.then = function (...args) {
+			const r = _then(...args);
 			_this.fixupAnimationPromise(r);
 
 			return r;
 		};
 		const _catch = promise.catch;
-		promise.catch = function () {
-			const r = _catch.apply(promise, arguments);
+		promise.catch = function (...args) {
+			const r = _catch(...args);
 			_this.fixupAnimationPromise(r);
 
 			return r;
@@ -138,7 +138,7 @@ export abstract class AnimationBase implements AnimationBaseDefinition {
 			throw new Error('No animation target specified.');
 		}
 
-		for (let item in animationDefinition) {
+		for (const item in animationDefinition) {
 			const value = animationDefinition[item];
 			if (value === undefined) {
 				continue;

packages/core/ui/animation/animation-interfaces.ts

@@ -18,7 +18,10 @@ export type TransformFunctionsInfo = {
 	scale: Pair;
 };
 
-export type AnimationPromise = Promise<void> & Cancelable;
+export interface AnimationPromise extends Promise<any>, Cancelable {
+	then(...args):AnimationPromise
+	catch(...args):AnimationPromise
+};
 
 export interface Pair {
 	x: number;

packages/core/ui/animation/index.android.ts

@@ -21,14 +21,14 @@ function ensureArgbEvaluator() {
 	}
 }
 
-let easeIn = lazy(() => new android.view.animation.AccelerateInterpolator(1));
-let easeOut = lazy(() => new android.view.animation.DecelerateInterpolator(1));
-let easeInOut = lazy(() => new android.view.animation.AccelerateDecelerateInterpolator());
-let linear = lazy(() => new android.view.animation.LinearInterpolator());
-let bounce = lazy(() => new android.view.animation.BounceInterpolator());
+const easeIn = lazy(() => new android.view.animation.AccelerateInterpolator(1));
+const easeOut = lazy(() => new android.view.animation.DecelerateInterpolator(1));
+const easeInOut = lazy(() => new android.view.animation.AccelerateDecelerateInterpolator());
+const linear = lazy(() => new android.view.animation.LinearInterpolator());
+const bounce = lazy(() => new android.view.animation.BounceInterpolator());
 
-let keyPrefix = 'ui.animation.';
-let propertyKeys = {};
+const keyPrefix = 'ui.animation.';
+const propertyKeys = {};
 propertyKeys[Properties.backgroundColor] = Symbol(keyPrefix + Properties.backgroundColor);
 propertyKeys[Properties.opacity] = Symbol(keyPrefix + Properties.opacity);
 propertyKeys[Properties.rotate] = Symbol(keyPrefix + Properties.rotate);
@@ -92,7 +92,7 @@ function getAndroidRepeatCount(iterations: number): number {
 }
 
 function createObjectAnimator(nativeView: android.view.View, propertyName: string, value: number): android.animation.ObjectAnimator {
-	let arr = Array.create('float', 1);
+	const arr = Array.create('float', 1);
 	arr[0] = value;
 
 	return android.animation.ObjectAnimator.ofFloat(nativeView, propertyName, arr);
@@ -126,7 +126,7 @@ export class Animation extends AnimationBase {
 	private _propertyResetCallbacks: Array<Function>;
 	private _valueSource: 'animation' | 'keyframe';
 	private _target: View;
-	private _resetOnFinish: boolean = true;
+	private _resetOnFinish = true;
 
 	constructor(animationDefinitions: Array<AnimationDefinitionInternal>, playSequentially?: boolean) {
 		super(animationDefinitions, playSequentially);
@@ -136,7 +136,7 @@ export class Animation extends AnimationBase {
 			this._valueSource = animationDefinitions[0].valueSource;
 		}
 
-		let that = new WeakRef(this);
+		const that = new WeakRef(this);
 		this._animatorListener = new android.animation.Animator.AnimatorListener({
 			onAnimationStart: function (animator: android.animation.Animator): void {
 				if (Trace.isEnabled()) {
@@ -300,7 +300,7 @@ export class Animation extends AnimationBase {
 		let originalValue3;
 		const density = layout.getDisplayDensity();
 
-		let key = propertyKeys[propertyAnimation.property];
+		const key = propertyKeys[propertyAnimation.property];
 		if (key) {
 			propertyAnimation.target[key] = propertyAnimation;
 		}
@@ -313,7 +313,7 @@ export class Animation extends AnimationBase {
 			};
 		}
 
-		let setLocal = this._valueSource === 'animation';
+		const setLocal = this._valueSource === 'animation';
 		const style = propertyAnimation.target.style;
 		switch (propertyAnimation.property) {
 			case Properties.opacity:
@@ -340,7 +340,7 @@ export class Animation extends AnimationBase {
 				animators.push(createObjectAnimator(nativeView, 'alpha', propertyAnimation.value));
 				break;
 
-			case Properties.backgroundColor:
+			case Properties.backgroundColor:{
 				backgroundColorProperty._initDefaultNativeValue(style);
 
 				ensureArgbEvaluator();
@@ -348,11 +348,11 @@ export class Animation extends AnimationBase {
 				const nativeArray = Array.create(java.lang.Object, 2);
 				nativeArray[0] = propertyAnimation.target.backgroundColor ? java.lang.Integer.valueOf((<Color>propertyAnimation.target.backgroundColor).argb) : java.lang.Integer.valueOf(-1);
 				nativeArray[1] = java.lang.Integer.valueOf((<Color>propertyAnimation.value).argb);
-				let animator = android.animation.ValueAnimator.ofObject(argbEvaluator, nativeArray);
+				const animator = android.animation.ValueAnimator.ofObject(argbEvaluator, nativeArray);
 				animator.addUpdateListener(
 					new android.animation.ValueAnimator.AnimatorUpdateListener({
 						onAnimationUpdate(animator: android.animation.ValueAnimator) {
-							let argb = (<java.lang.Integer>animator.getAnimatedValue()).intValue();
+							const argb = (<java.lang.Integer>animator.getAnimatedValue()).intValue();
 							propertyAnimation.target.style[setLocal ? backgroundColorProperty.name : backgroundColorProperty.keyframe] = new Color(argb);
 						},
 					})
@@ -378,7 +378,7 @@ export class Animation extends AnimationBase {
 				);
 				animators.push(animator);
 				break;
-
+			}
 			case Properties.translate:
 				translateXProperty._initDefaultNativeValue(style);
 				translateYProperty._initDefaultNativeValue(style);
@@ -494,18 +494,18 @@ export class Animation extends AnimationBase {
 				extentProperty._initDefaultNativeValue(style);
 				const nativeArray = Array.create('float', 2);
 				let toValue = propertyAnimation.value;
-				let parent = propertyAnimation.target.parent as View;
+				const parent = propertyAnimation.target.parent as View;
 				if (!parent) {
 					throw new Error(`cannot animate ${propertyAnimation.property} on root view`);
 				}
 				const parentExtent: number = isVertical ? parent.getMeasuredHeight() : parent.getMeasuredWidth();
 				toValue = PercentLength.toDevicePixels(toValue, parentExtent, parentExtent) / Screen.mainScreen.scale;
-				let nativeHeight: number = isVertical ? nativeView.getHeight() : nativeView.getWidth();
+				const nativeHeight: number = isVertical ? nativeView.getHeight() : nativeView.getWidth();
 				const targetStyle: string = setLocal ? extentProperty.name : extentProperty.keyframe;
 				originalValue1 = nativeHeight / Screen.mainScreen.scale;
 				nativeArray[0] = originalValue1;
 				nativeArray[1] = toValue;
-				let extentAnimator = android.animation.ValueAnimator.ofFloat(nativeArray);
+				const extentAnimator = android.animation.ValueAnimator.ofFloat(nativeArray);
 				extentAnimator.addUpdateListener(
 					new android.animation.ValueAnimator.AnimatorUpdateListener({
 						onAnimationUpdate(animator: android.animation.ValueAnimator) {

packages/core/ui/animation/index.ios.ts

@@ -14,10 +14,10 @@ import { Screen } from '../../platform';
 export * from './animation-common';
 export { KeyframeAnimation, KeyframeAnimationInfo, KeyframeDeclaration, KeyframeInfo } from './keyframe-animation';
 
-let _transform = '_transform';
-let _skip = '_skip';
+const _transform = '_transform';
+const _skip = '_skip';
 
-let FLT_MAX = 340282346638528859811704183484516925440.0;
+const FLT_MAX = 340282346638528859811704183484516925440.0;
 
 class AnimationInfo {
 	public propertyNameToAnimate: string;
@@ -41,7 +41,7 @@ class AnimationDelegateImpl extends NSObject implements CAAnimationDelegate {
 	private _valueSource: 'animation' | 'keyframe';
 
 	public static initWithFinishedCallback(finishedCallback: Function, propertyAnimation: PropertyAnimationInfo, valueSource: 'animation' | 'keyframe'): AnimationDelegateImpl {
-		let delegate = <AnimationDelegateImpl>AnimationDelegateImpl.new();
+		const delegate = <AnimationDelegateImpl>AnimationDelegateImpl.new();
 		delegate._finishedCallback = finishedCallback;
 		delegate._propertyAnimation = propertyAnimation;
 		delegate._valueSource = valueSource;
@@ -50,9 +50,9 @@ class AnimationDelegateImpl extends NSObject implements CAAnimationDelegate {
 	}
 
 	animationDidStart(anim: CAAnimation): void {
-		let value = this._propertyAnimation.value;
-		let setLocal = this._valueSource === 'animation';
-		let targetStyle = this._propertyAnimation.target.style;
+		const value = this._propertyAnimation.value;
+		const setLocal = this._valueSource === 'animation';
+		const targetStyle = this._propertyAnimation.target.style;
 
 		(<IOSView>this._propertyAnimation.target)._suspendPresentationLayerUpdates();
 
@@ -93,8 +93,8 @@ class AnimationDelegateImpl extends NSObject implements CAAnimationDelegate {
 					targetStyle[setLocal ? rotateProperty.name : rotateProperty.keyframe] = value[Properties.rotate].z;
 				}
 				if (value[Properties.scale] !== undefined) {
-					let x = value[Properties.scale].x;
-					let y = value[Properties.scale].y;
+					const x = value[Properties.scale].x;
+					const y = value[Properties.scale].y;
 					targetStyle[setLocal ? scaleXProperty.name : scaleXProperty.keyframe] = x === 0 ? 0.001 : x;
 					targetStyle[setLocal ? scaleYProperty.name : scaleYProperty.keyframe] = y === 0 ? 0.001 : y;
 				}
@@ -132,7 +132,7 @@ export function _resolveAnimationCurve(curve: string | CubicBezierAnimationCurve
 			if (curve instanceof CAMediaTimingFunction) {
 				return curve;
 			} else if (curve instanceof CubicBezierAnimationCurve) {
-				let animationCurve = <CubicBezierAnimationCurve>curve;
+				const animationCurve = <CubicBezierAnimationCurve>curve;
 
 				return CAMediaTimingFunction.functionWithControlPoints(animationCurve.x1, animationCurve.y1, animationCurve.x2, animationCurve.y2);
 			} else {
@@ -168,8 +168,8 @@ export class Animation extends AnimationBase {
 			this._mergedPropertyAnimations = this._propertyAnimations;
 		}
 
-		let that = this;
-		let animationFinishedCallback = (cancelled: boolean) => {
+		const that = this;
+		const animationFinishedCallback = (cancelled: boolean) => {
 			if (that._playSequentially) {
 				// This function will be called by the last animation when done or by another animation if the user cancels them halfway through.
 				if (cancelled) {
@@ -207,7 +207,7 @@ export class Animation extends AnimationBase {
 			return this._rejectAlreadyPlaying();
 		}
 
-		let animationFinishedPromise = super.play();
+		const animationFinishedPromise = super.play();
 		this._finishedAnimations = 0;
 		this._cancelledAnimations = 0;
 		this._iOSAnimationFunction();
@@ -223,9 +223,9 @@ export class Animation extends AnimationBase {
 		}
 
 		let i = 0;
-		let length = this._mergedPropertyAnimations.length;
+		const length = this._mergedPropertyAnimations.length;
 		for (; i < length; i++) {
-			let propertyAnimation = this._mergedPropertyAnimations[i];
+			const propertyAnimation = this._mergedPropertyAnimations[i];
 			propertyAnimation.target.nativeViewProtected.layer.removeAllAnimations();
 			if (propertyAnimation._propertyResetCallback) {
 				propertyAnimation._propertyResetCallback(propertyAnimation._originalValue, this._valueSource);
@@ -248,8 +248,8 @@ export class Animation extends AnimationBase {
 				return;
 			}
 
-			let animation = propertyAnimations[index];
-			let args = Animation._getNativeAnimationArguments(animation, valueSource);
+			const animation = propertyAnimations[index];
+			const args = Animation._getNativeAnimationArguments(animation, valueSource);
 
 			if (animation.curve === 'spring') {
 				Animation._createNativeSpringAnimation(propertyAnimations, index, playSequentially, args, animation, valueSource, finishedCallback);
@@ -269,7 +269,7 @@ export class Animation extends AnimationBase {
 		let subPropertyNameToAnimate;
 		let toValue = animation.value;
 		let fromValue;
-		let setLocal = valueSource === 'animation';
+		const setLocal = valueSource === 'animation';
 
 		switch (animation.property) {
 			case Properties.backgroundColor:
@@ -380,7 +380,7 @@ export class Animation extends AnimationBase {
 				toValue = NSValue.valueWithCATransform3D(Animation._createNativeAffineTransform(animation));
 				break;
 			case Properties.width:
-			case Properties.height:
+			case Properties.height:{
 				const direction: string = animation.property;
 				const isHeight: boolean = direction === 'height';
 				propertyNameToAnimate = 'bounds';
@@ -389,9 +389,9 @@ export class Animation extends AnimationBase {
 				}
 				const parentExtent: number = isHeight ? parent.getMeasuredHeight() : parent.getMeasuredWidth();
 				const asNumber = PercentLength.toDevicePixels(PercentLength.parse(toValue), parentExtent, parentExtent) / Screen.mainScreen.scale;
-				let currentBounds = nativeView.layer.bounds;
-				let extentX = isHeight ? currentBounds.size.width : asNumber;
-				let extentY = isHeight ? asNumber : currentBounds.size.height;
+				const currentBounds = nativeView.layer.bounds;
+				const extentX = isHeight ? currentBounds.size.width : asNumber;
+				const extentY = isHeight ? asNumber : currentBounds.size.height;
 				fromValue = NSValue.valueWithCGRect(currentBounds);
 				toValue = NSValue.valueWithCGRect(CGRectMake(currentBounds.origin.x, currentBounds.origin.y, extentX, extentY));
 				animation._originalValue = view.height;
@@ -400,6 +400,7 @@ export class Animation extends AnimationBase {
 					style[setLocal ? prop.name : prop.keyframe] = value;
 				};
 				break;
+			}
 			default:
 				throw new Error(`Animating property '${animation.property}' is unsupported`);
 		}
@@ -435,7 +436,7 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _createNativeAnimation(propertyAnimations: Array<PropertyAnimation>, index: number, playSequentially: boolean, args: AnimationInfo, animation: PropertyAnimation, valueSource: 'animation' | 'keyframe', finishedCallback: (cancelled?: boolean) => void) {
-		let nativeView = <UIView>animation.target.nativeViewProtected;
+		const nativeView = <UIView>animation.target.nativeViewProtected;
 		let nativeAnimation;
 
 		if (args.subPropertiesToAnimate) {
@@ -444,7 +445,7 @@ export class Animation extends AnimationBase {
 			nativeAnimation = this._createBasicAnimation(args, animation);
 		}
 
-		let animationDelegate = AnimationDelegateImpl.initWithFinishedCallback(finishedCallback, animation, valueSource);
+		const animationDelegate = AnimationDelegateImpl.initWithFinishedCallback(finishedCallback, animation, valueSource);
 		nativeAnimation.setValueForKey(animationDelegate, 'delegate');
 
 		nativeView.layer.addAnimationForKey(nativeAnimation, args.propertyNameToAnimate);
@@ -461,7 +462,7 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _createGroupAnimation(args: AnimationInfo, animation: PropertyAnimation) {
-		let groupAnimation = CAAnimationGroup.new();
+		const groupAnimation = CAAnimationGroup.new();
 		groupAnimation.duration = args.duration;
 		const animations = NSMutableArray.alloc<CAAnimation>().initWithCapacity(3);
 
@@ -481,7 +482,7 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _createBasicAnimation(args: AnimationInfo, animation: PropertyAnimation) {
-		let basicAnimation = CABasicAnimation.animationWithKeyPath(args.propertyNameToAnimate);
+		const basicAnimation = CABasicAnimation.animationWithKeyPath(args.propertyNameToAnimate);
 		basicAnimation.fromValue = args.fromValue;
 		basicAnimation.toValue = args.toValue;
 		basicAnimation.duration = args.duration;
@@ -499,7 +500,7 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _createNativeSpringAnimation(propertyAnimations: Array<PropertyAnimationInfo>, index: number, playSequentially: boolean, args: AnimationInfo, animation: PropertyAnimationInfo, valueSource: 'animation' | 'keyframe', finishedCallback: (cancelled?: boolean) => void) {
-		let nativeView = <UIView>animation.target.nativeViewProtected;
+		const nativeView = <UIView>animation.target.nativeViewProtected;
 
 		let callback = undefined;
 		let nextAnimation;
@@ -575,7 +576,7 @@ export class Animation extends AnimationBase {
 					}
 				}
 				if (finishedCallback) {
-					let cancelled = !animationDidFinish;
+					const cancelled = !animationDidFinish;
 					finishedCallback(cancelled);
 				}
 				if (animationDidFinish && nextAnimation) {
@@ -586,18 +587,18 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _createNativeAffineTransform(animation: PropertyAnimation): CATransform3D {
-		let value = animation.value;
+		const value = animation.value;
 		let result: CATransform3D = CATransform3DIdentity;
 
 		if (value[Properties.translate] !== undefined) {
-			let x = value[Properties.translate].x;
-			let y = value[Properties.translate].y;
+			const x = value[Properties.translate].x;
+			const y = value[Properties.translate].y;
 			result = CATransform3DTranslate(result, x, y, 0);
 		}
 
 		if (value[Properties.scale] !== undefined) {
-			let x = value[Properties.scale].x;
-			let y = value[Properties.scale].y;
+			const x = value[Properties.scale].x;
+			const y = value[Properties.scale].y;
 			result = CATransform3DScale(result, x === 0 ? 0.001 : x, y === 0 ? 0.001 : y, 1);
 		}
 
@@ -609,17 +610,17 @@ export class Animation extends AnimationBase {
 	}
 
 	private static _canBeMerged(animation1: PropertyAnimation, animation2: PropertyAnimation) {
-		let result = Animation._isAffineTransform(animation1.property) && Animation._isAffineTransform(animation2.property) && animation1.target === animation2.target && animation1.duration === animation2.duration && animation1.delay === animation2.delay && animation1.iterations === animation2.iterations && animation1.curve === animation2.curve;
+		const result = Animation._isAffineTransform(animation1.property) && Animation._isAffineTransform(animation2.property) && animation1.target === animation2.target && animation1.duration === animation2.duration && animation1.delay === animation2.delay && animation1.iterations === animation2.iterations && animation1.curve === animation2.curve;
 
 		return result;
 	}
 
 	private static _mergeAffineTransformAnimations(propertyAnimations: Array<PropertyAnimation>): Array<PropertyAnimation> {
-		let result = new Array<PropertyAnimation>();
+		const result = new Array<PropertyAnimation>();
 
 		let i = 0;
 		let j;
-		let length = propertyAnimations.length;
+		const length = propertyAnimations.length;
 		for (; i < length; i++) {
 			if (propertyAnimations[i][_skip]) {
 				continue;
@@ -636,7 +637,7 @@ export class Animation extends AnimationBase {
 				//    rotate: 90,
 				//    scale: {x: 2, y: 2 }
 				// }
-				let newTransformAnimation: PropertyAnimation = {
+				const newTransformAnimation: PropertyAnimation = {
 					target: propertyAnimations[i].target,
 					property: _transform,
 					value: {},

packages/core/ui/animation/keyframe-animation.ts

@@ -58,8 +58,8 @@ interface Keyframe {
 
 export class KeyframeAnimation {
 	public animations: Array<Keyframe>;
-	public delay: number = 0;
-	public iterations: number = 1;
+	public delay = 0;
+	public iterations = 1;
 
 	private _resolve;
 	private _isPlaying: boolean;
@@ -69,22 +69,22 @@ export class KeyframeAnimation {
 
 	public static keyframeAnimationFromInfo(info: KeyframeAnimationInfo): KeyframeAnimation {
 		const length = info.keyframes.length;
-		let animations = new Array<Keyframe>();
+		const animations = new Array<Keyframe>();
 		let startDuration = 0;
 
 		if (info.isReverse) {
 			for (let index = length - 1; index >= 0; index--) {
-				let keyframe = info.keyframes[index];
+				const keyframe = info.keyframes[index];
 				startDuration = KeyframeAnimation.parseKeyframe(info, keyframe, animations, startDuration);
 			}
 		} else {
 			for (let index = 0; index < length; index++) {
-				let keyframe = info.keyframes[index];
+				const keyframe = info.keyframes[index];
 				startDuration = KeyframeAnimation.parseKeyframe(info, keyframe, animations, startDuration);
 			}
 			for (let index = length - 1; index > 0; index--) {
-				let a1 = animations[index];
-				let a2 = animations[index - 1];
+				const a1 = animations[index];
+				const a2 = animations[index - 1];
 				if (a2['curve'] !== undefined) {
 					a1['curve'] = a2['curve'];
 					a2['curve'] = undefined;
@@ -104,8 +104,8 @@ export class KeyframeAnimation {
 	}
 
 	private static parseKeyframe(info: KeyframeAnimationInfo, keyframe: KeyframeInfo, animations: Array<Object>, startDuration: number): number {
-		let animation: Keyframe = {};
-		for (let declaration of keyframe.declarations) {
+		const animation: Keyframe = {};
+		for (const declaration of keyframe.declarations) {
 			animation[declaration.property] = declaration.value;
 		}
 
@@ -138,13 +138,13 @@ export class KeyframeAnimation {
 
 		this._isPlaying = false;
 		for (let i = this._nativeAnimations.length - 1; i >= 0; i--) {
-			let animation = this._nativeAnimations[i];
+			const animation = this._nativeAnimations[i];
 			if (animation.isPlaying) {
 				animation.cancel();
 			}
 		}
 		if (this._nativeAnimations.length > 0) {
-			let animation = this._nativeAnimations[0];
+			const animation = this._nativeAnimations[0];
 			this._resetAnimationValues(this._target, animation);
 		}
 		this._resetAnimations();
@@ -159,7 +159,7 @@ export class KeyframeAnimation {
 			});
 		}
 
-		let animationFinishedPromise = new Promise<void>((resolve) => {
+		const animationFinishedPromise = new Promise<void>((resolve) => {
 			this._resolve = resolve;
 		});
 
@@ -181,7 +181,7 @@ export class KeyframeAnimation {
 			return;
 		}
 		if (index === 0) {
-			let animation = this.animations[0];
+			const animation = this.animations[0];
 
 			if ('backgroundColor' in animation) {
 				view.style[backgroundColorProperty.keyframe] = animation.backgroundColor;
@@ -216,7 +216,7 @@ export class KeyframeAnimation {
 				this.animate(view, 0, iterations);
 			} else {
 				if (this._isForwards === false) {
-					let animation = this.animations[this.animations.length - 1];
+					const animation = this.animations[this.animations.length - 1];
 					this._resetAnimationValues(view, animation);
 				}
 				this._resolveAnimationFinishedPromise();
@@ -228,7 +228,7 @@ export class KeyframeAnimation {
 			if (cachedAnimation) {
 				animation = cachedAnimation;
 			} else {
-				let animationDef = this.animations[index];
+				const animationDef = this.animations[index];
 				(<any>animationDef).target = view;
 				animation = new Animation([animationDef]);
 				this._nativeAnimations.push(animation);

packages/core/ui/bottom-navigation/index.ios.ts

@@ -400,7 +400,7 @@ export class BottomNavigation extends TabNavigationBase {
 		}
 	}
 
-	private setIconColor(tabStripItem: TabStripItem, forceReload: boolean = false): void {
+	private setIconColor(tabStripItem: TabStripItem, forceReload = false): void {
 		if (forceReload || (!this._unSelectedItemColor && !this._selectedItemColor)) {
 			// if selectedItemColor or unSelectedItemColor is set we don't respect the color from the style
 			const tabStripColor = this.selectedIndex === tabStripItem._index ? this._selectedItemColor : this._unSelectedItemColor;

packages/core/ui/builder/binding-builder.ts

@@ -1,7 +1,7 @@
 // regex that contains all symbols applicable for expression used to AI detect an expression.
-const expressionSymbolsRegex = /[\+\-\*\/%\?:<>=!\|&\(\)^~]/;
+const expressionSymbolsRegex = /[+-*/%?:<>=!|&()^~]/;
 
-export module bindingConstants {
+export namespace bindingConstants {
 	export const sourceProperty = 'sourceProperty';
 	export const targetProperty = 'targetProperty';
 	export const expression = 'expression';
@@ -185,7 +185,7 @@ export function getBindingOptions(name: string, value: string): any {
 		targetProperty: name,
 	};
 
-	for (let prop in bindingOptionsParameters) {
+	for (const prop in bindingOptionsParameters) {
 		if (bindingOptionsParameters.hasOwnProperty(prop)) {
 			bindOptions[prop] = bindingOptionsParameters[prop];
 		}

packages/core/ui/builder/component-builder/index.ts

@@ -100,6 +100,7 @@ const createComponentInstance = profile('createComponentInstance', (elementName:
 		// Create instance of the component.
 		instance = new instanceType();
 	} catch (ex) {
+		// eslint-disable-next-line @typescript-eslint/no-var-requires
 		const debug: typeof debugModule = require('../../../utils/debug');
 		throw new debug.ScopeError(ex, "Module '" + (resolvedModuleName || elementName) + "' not found for element '" + (namespace ? namespace + ':' : '') + elementName + "'.");
 	}
@@ -131,7 +132,7 @@ const applyComponentCss = profile('applyComponentCss', (instance: View, moduleNa
 	let cssApplied = false;
 
 	if (attributes && attributes[CSS_FILE]) {
-		let resolvedCssModuleName = resolveModuleName(sanitizeModuleName(attributes[CSS_FILE]), 'css');
+		const resolvedCssModuleName = resolveModuleName(sanitizeModuleName(attributes[CSS_FILE]), 'css');
 
 		if (resolvedCssModuleName) {
 			instance.addCssFile(resolvedCssModuleName);
@@ -142,7 +143,7 @@ const applyComponentCss = profile('applyComponentCss', (instance: View, moduleNa
 	}
 
 	if (moduleName && !cssApplied) {
-		let resolvedCssModuleName = resolveModuleName(moduleName, 'css');
+		const resolvedCssModuleName = resolveModuleName(moduleName, 'css');
 		if (resolvedCssModuleName) {
 			instance.addCssFile(resolvedCssModuleName);
 		}
@@ -252,7 +253,7 @@ function isBinding(value: any): boolean {
 }
 
 // For example, ListView.itemTemplateSelector
-let KNOWN_FUNCTIONS = 'knownFunctions';
+const KNOWN_FUNCTIONS = 'knownFunctions';
 function isKnownFunction(name: string, instance: View): boolean {
 	return instance.constructor && KNOWN_FUNCTIONS in instance.constructor && instance.constructor[KNOWN_FUNCTIONS].indexOf(name) !== -1;
 }

packages/core/ui/builder/index.ts

@@ -44,7 +44,7 @@ export class Builder {
 		} else if (entry.moduleName) {
 			const moduleName = sanitizeModuleName(entry.moduleName);
 			const resolvedCodeModuleName = resolveModuleName(moduleName, ''); //`${moduleName}.xml`;
-			let moduleExports = resolvedCodeModuleName ? global.loadModule(resolvedCodeModuleName, true) : null;
+			const moduleExports = resolvedCodeModuleName ? global.loadModule(resolvedCodeModuleName, true) : null;
 
 			if (moduleExports && moduleExports.createPage) {
 				// Exports has a createPage() method
@@ -147,7 +147,7 @@ function loadInternal(moduleName: string, moduleExports: any): ComponentModule {
 	return componentModule;
 }
 
-function loadCustomComponent(componentNamespace: string, componentName?: string, attributes?: Object, context?: Object, parentPage?: View, isRootComponent: boolean = true, moduleNamePath?: string): ComponentModule {
+function loadCustomComponent(componentNamespace: string, componentName?: string, attributes?: Object, context?: Object, parentPage?: View, isRootComponent = true, moduleNamePath?: string): ComponentModule {
 	if (!parentPage && context) {
 		// Read the parent page that was passed down below
 		// https://github.com/NativeScript/NativeScript/issues/1639
@@ -183,7 +183,7 @@ function loadCustomComponent(componentNamespace: string, componentName?: string,
 
 		// Attributes will be transferred to the custom component
 		if (isDefined(result) && isDefined(result.component) && isDefined(attributes)) {
-			for (let attr in attributes) {
+			for (const attr in attributes) {
 				setPropertyValue(result.component, subExports, context, attr, attributes[attr]);
 			}
 		}
@@ -489,7 +489,7 @@ namespace xml2ui {
 				this._state = TemplateParser.State.FINISHED;
 
 				if (this._setTemplateProperty && this._templateProperty.name in this._templateProperty.parent.component) {
-					let template = this.buildTemplate();
+					const template = this.buildTemplate();
 					this._templateProperty.parent.component[this._templateProperty.name] = template;
 				}
 			}
@@ -528,7 +528,7 @@ namespace xml2ui {
 
 		public parse(args: xml.ParserEvent): XmlStateConsumer {
 			if (args.eventType === xml.ParserEventType.StartElement && args.elementName === 'template') {
-				let childParser = new TemplateParser(this, this.templateProperty, false);
+				const childParser = new TemplateParser(this, this.templateProperty, false);
 				childParser['key'] = args.attributes['key'];
 				this._childParsers.push(childParser);
 
@@ -536,9 +536,9 @@ namespace xml2ui {
 			}
 
 			if (args.eventType === xml.ParserEventType.EndElement) {
-				let name = ComponentParser.getComplexPropertyName(args.elementName);
+				const name = ComponentParser.getComplexPropertyName(args.elementName);
 				if (name === this.templateProperty.name) {
-					let templates = new Array<KeyedTemplate>();
+					const templates = new Array<KeyedTemplate>();
 					for (let i = 0; i < this._childParsers.length; i++) {
 						templates.push({
 							key: this._childParsers[i]['key'],

packages/core/ui/builder/module-name-sanitizer.ts

@@ -3,7 +3,7 @@
  * @param moduleName the name
  * @param removeExtension whether to remove extension
  */
-export function sanitizeModuleName(moduleName: string, removeExtension: boolean = true): string {
+export function sanitizeModuleName(moduleName: string, removeExtension = true): string {
 	moduleName = moduleName.trim();
 
 	if (moduleName.startsWith('~/')) {

packages/core/ui/button/index.ios.ts

@@ -66,8 +66,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[borderTopWidthProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let top = layout.toDeviceIndependentPixels(this.effectivePaddingTop + this.effectiveBorderTopWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const top = layout.toDeviceIndependentPixels(this.effectivePaddingTop + this.effectiveBorderTopWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: top,
 			left: inset.left,
@@ -83,8 +83,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[borderRightWidthProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let right = layout.toDeviceIndependentPixels(this.effectivePaddingRight + this.effectiveBorderRightWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const right = layout.toDeviceIndependentPixels(this.effectivePaddingRight + this.effectiveBorderRightWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: inset.left,
@@ -100,8 +100,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[borderBottomWidthProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let bottom = layout.toDeviceIndependentPixels(this.effectivePaddingBottom + this.effectiveBorderBottomWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const bottom = layout.toDeviceIndependentPixels(this.effectivePaddingBottom + this.effectiveBorderBottomWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: inset.left,
@@ -117,8 +117,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[borderLeftWidthProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let left = layout.toDeviceIndependentPixels(this.effectivePaddingLeft + this.effectiveBorderLeftWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const left = layout.toDeviceIndependentPixels(this.effectivePaddingLeft + this.effectiveBorderLeftWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: left,
@@ -134,8 +134,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[paddingTopProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let top = layout.toDeviceIndependentPixels(this.effectivePaddingTop + this.effectiveBorderTopWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const top = layout.toDeviceIndependentPixels(this.effectivePaddingTop + this.effectiveBorderTopWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: top,
 			left: inset.left,
@@ -151,8 +151,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[paddingRightProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let right = layout.toDeviceIndependentPixels(this.effectivePaddingRight + this.effectiveBorderRightWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const right = layout.toDeviceIndependentPixels(this.effectivePaddingRight + this.effectiveBorderRightWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: inset.left,
@@ -168,8 +168,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[paddingBottomProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let bottom = layout.toDeviceIndependentPixels(this.effectivePaddingBottom + this.effectiveBorderBottomWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const bottom = layout.toDeviceIndependentPixels(this.effectivePaddingBottom + this.effectiveBorderBottomWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: inset.left,
@@ -185,8 +185,8 @@ export class Button extends ButtonBase {
 		};
 	}
 	[paddingLeftProperty.setNative](value: Length) {
-		let inset = this.nativeViewProtected.contentEdgeInsets;
-		let left = layout.toDeviceIndependentPixels(this.effectivePaddingLeft + this.effectiveBorderLeftWidth);
+		const inset = this.nativeViewProtected.contentEdgeInsets;
+		const left = layout.toDeviceIndependentPixels(this.effectivePaddingLeft + this.effectiveBorderLeftWidth);
 		this.nativeViewProtected.contentEdgeInsets = {
 			top: inset.top,
 			left: left,
@@ -235,7 +235,7 @@ export class Button extends ButtonBase {
 			return super.onMeasure(widthMeasureSpec, heightMeasureSpec);
 		}
 
-		let nativeView = this.nativeViewProtected;
+		const nativeView = this.nativeViewProtected;
 		if (nativeView) {
 			const width = layout.getMeasureSpecSize(widthMeasureSpec);
 			const widthMode = layout.getMeasureSpecMode(widthMeasureSpec);
@@ -271,7 +271,7 @@ class TapHandlerImpl extends NSObject {
 	private _owner: WeakRef<Button>;
 
 	public static initWithOwner(owner: WeakRef<Button>): TapHandlerImpl {
-		let handler = <TapHandlerImpl>TapHandlerImpl.new();
+		const handler = <TapHandlerImpl>TapHandlerImpl.new();
 		handler._owner = owner;
 		return handler;
 	}
@@ -279,7 +279,7 @@ class TapHandlerImpl extends NSObject {
 	public tap(args) {
 		// _owner is a {N} view which could get destroyed when a tap initiates (protect!)
 		if (this._owner) {
-			let owner = this._owner.get();
+			const owner = this._owner.get();
 			if (owner) {
 				owner._emit(ButtonBase.tapEvent);
 			}

packages/core/ui/content-view/index.ts

@@ -15,7 +15,7 @@ export class ContentView extends CustomLayoutView implements AddChildFromBuilder
 		return this._content;
 	}
 	set content(value: View) {
-		let oldView = this._content;
+		const oldView = this._content;
 		if (this._content) {
 			this._removeView(this._content);
 		}

packages/core/ui/core/bindable/index.ts

@@ -3,13 +3,14 @@ import { ViewBase } from '../view-base';
 
 // Requires
 import { unsetValue } from '../properties';
-import { Observable, WrappedValue, PropertyChangeData, EventData } from '../../../data/observable';
+import { Observable, PropertyChangeData } from '../../../data/observable';
 import { addWeakEventListener, removeWeakEventListener } from '../weak-event-listener';
 import { bindingConstants, parentsRegex } from '../../builder/binding-builder';
 import { escapeRegexSymbols } from '../../../utils';
 import { Trace } from '../../../trace';
 import * as types from '../../../utils/types';
 import * as bindableResources from './bindable-resources';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const polymerExpressions = require('../../../js-libs/polymer-expressions');
 import { PolymerExpressions } from '../../../js-libs/polymer-expressions';
 
@@ -94,7 +95,7 @@ export function getEventOrGestureName(name: string): string {
 
 // NOTE: method fromString from "ui/gestures";
 export function isGesture(eventOrGestureName: string): boolean {
-	let t = eventOrGestureName.trim().toLowerCase();
+	const t = eventOrGestureName.trim().toLowerCase();
 
 	return t === 'tap' || t === 'doubletap' || t === 'pinch' || t === 'pan' || t === 'swipe' || t === 'rotation' || t === 'longpress' || t === 'touch';
 }
@@ -103,8 +104,8 @@ export function isGesture(eventOrGestureName: string): boolean {
 // in controls. They will just override this one and provide their own event support.
 export function isEventOrGesture(name: string, view: ViewBase): boolean {
 	if (typeof name === 'string') {
-		let eventOrGestureName = getEventOrGestureName(name);
-		let evt = `${eventOrGestureName}Event`;
+		const eventOrGestureName = getEventOrGestureName(name);
+		const evt = `${eventOrGestureName}Event`;
 
 		return (view.constructor && evt in view.constructor) || isGesture(eventOrGestureName.toLowerCase());
 	}
@@ -149,7 +150,7 @@ export class Binding {
 	}
 
 	public loadedHandlerVisualTreeBinding(args) {
-		let target = args.object;
+		const target = args.object;
 		target.off('loaded', this.loadedHandlerVisualTreeBinding, this);
 		const context = target.bindingContext;
 		if (context !== undefined && context !== null) {
@@ -176,7 +177,7 @@ export class Binding {
 
 	private sourceAsObject(source: any): any {
 		/* tslint:disable */
-		let objectType = typeof source;
+		const objectType = typeof source;
 		if (objectType === 'number') {
 			source = new Number(source);
 		} else if (objectType === 'boolean') {
@@ -228,12 +229,12 @@ export class Binding {
 			this.source = new WeakRef(source);
 			this.sourceOptions = this.resolveOptions(source, this.sourceProperties);
 
-			let sourceValue = this.getSourcePropertyValue();
+			const sourceValue = this.getSourcePropertyValue();
 			this.updateTarget(sourceValue);
 			this.addPropertyChangeListeners(this.source, this.sourceProperties);
 		} else if (!this.sourceIsBindingContext) {
 			// TODO: if oneWay - call target.unbind();
-			let sourceValue = this.getSourcePropertyValue();
+			const sourceValue = this.getSourcePropertyValue();
 			this.updateTarget(sourceValue ? sourceValue : source);
 		}
 	}
@@ -264,21 +265,21 @@ export class Binding {
 
 	// Consider returning single {} instead of array for performance.
 	private resolveObjectsAndProperties(source: Object, properties: Array<string>): Array<{ instance: Object; property: string }> {
-		let result = [];
+		const result = [];
 		let currentObject = source;
 		let currentObjectChanged = false;
 		for (let i = 0, propsArrayLength = properties.length; i < propsArrayLength; i++) {
-			let property = properties[i];
+			const property = properties[i];
 			if (property === bc.bindingValueKey) {
 				currentObjectChanged = true;
 			}
 
 			if (property === bc.parentValueKey || property.indexOf(bc.parentsValueKey) === 0) {
-				let parentView = this.getParentView(this.target.get(), property).view;
+				const parentView = this.getParentView(this.target.get(), property).view;
 				if (parentView) {
 					currentObject = parentView.bindingContext;
 				} else {
-					let targetInstance = this.target.get();
+					const targetInstance = this.target.get();
 					targetInstance.off('loaded', this.loadedHandlerVisualTreeBinding, this);
 					targetInstance.on('loaded', this.loadedHandlerVisualTreeBinding, this);
 				}
@@ -304,13 +305,13 @@ export class Binding {
 	}
 
 	private addPropertyChangeListeners(source: WeakRef<Object>, sourceProperty: Array<string>, parentProperies?: string) {
-		let objectsAndProperties = this.resolveObjectsAndProperties(source.get(), sourceProperty);
+		const objectsAndProperties = this.resolveObjectsAndProperties(source.get(), sourceProperty);
 		let prop = parentProperies || '';
 
 		for (let i = 0, length = objectsAndProperties.length; i < length; i++) {
 			const propName = objectsAndProperties[i].property;
 			prop += '$' + propName;
-			let currentObject = objectsAndProperties[i].instance;
+			const currentObject = objectsAndProperties[i].instance;
 			if (!this.propertyChangeListeners.has(prop) && currentObject instanceof Observable && currentObject._isViewBase) {
 				// Add listener for properties created with after 3.0 version
 				addWeakEventListener(currentObject, `${propName}Change`, this.onSourcePropertyChanged, this);
@@ -330,9 +331,9 @@ export class Binding {
 		// text="{{ sourceProperty = $parents['ListView'].test, expression = $parents['ListView'].test + 2}}"
 		// update expression will be '$newPropertyValue + 2'
 		// then on expression execution the new value will be taken and target property will be updated with the value of the expression.
-		let escapedSourceProperty = escapeRegexSymbols(this.options.sourceProperty);
-		let expRegex = new RegExp(escapedSourceProperty, 'g');
-		let resultExp = this.options.expression.replace(expRegex, bc.newPropertyValueKey);
+		const escapedSourceProperty = escapeRegexSymbols(this.options.sourceProperty);
+		const expRegex = new RegExp(escapedSourceProperty, 'g');
+		const resultExp = this.options.expression.replace(expRegex, bc.newPropertyValueKey);
 
 		return resultExp;
 	}
@@ -344,7 +345,7 @@ export class Binding {
 
 		let newValue = value;
 		if (this.options.expression) {
-			let changedModel = {};
+			const changedModel = {};
 			changedModel[bc.bindingValueKey] = value;
 			changedModel[bc.newPropertyValueKey] = value;
 			let sourcePropertyName = '';
@@ -358,10 +359,10 @@ export class Binding {
 				changedModel[sourcePropertyName] = value;
 			}
 
-			let updateExpression = this.prepareExpressionForUpdate();
+			const updateExpression = this.prepareExpressionForUpdate();
 			this.prepareContextForExpression(changedModel, updateExpression, undefined);
 
-			let expressionValue = this._getExpressionValue(updateExpression, true, changedModel);
+			const expressionValue = this._getExpressionValue(updateExpression, true, changedModel);
 			if (expressionValue instanceof Error) {
 				Trace.write((<Error>expressionValue).message, Trace.categories.Binding, Trace.messageType.error);
 			}
@@ -374,13 +375,13 @@ export class Binding {
 
 	private _getExpressionValue(expression: string, isBackConvert: boolean, changedModel: any): any {
 		try {
-			let exp = PolymerExpressions.getExpression(expression);
+			const exp = PolymerExpressions.getExpression(expression);
 			if (exp) {
-				let context = (this.source && this.source.get && this.source.get()) || global;
-				let model = {};
-				let addedProps = [];
+				const context = (this.source && this.source.get && this.source.get()) || global;
+				const model = {};
+				const addedProps = [];
 				const resources = bindableResources.get();
-				for (let prop in resources) {
+				for (const prop in resources) {
 					if (resources.hasOwnProperty(prop) && !context.hasOwnProperty(prop)) {
 						context[prop] = resources[prop];
 						addedProps.push(prop);
@@ -389,9 +390,9 @@ export class Binding {
 
 				this.prepareContextForExpression(context, expression, addedProps);
 				model[contextKey] = context;
-				let result = exp.getValue(model, isBackConvert, changedModel ? changedModel : model);
+				const result = exp.getValue(model, isBackConvert, changedModel ? changedModel : model);
 				// clear added props
-				let addedPropsLength = addedProps.length;
+				const addedPropsLength = addedProps.length;
 				for (let i = 0; i < addedPropsLength; i++) {
 					delete context[addedProps[i]];
 				}
@@ -402,7 +403,7 @@ export class Binding {
 
 			return new Error(expression + ' is not a valid expression.');
 		} catch (e) {
-			let errorMessage = 'Run-time error occured in file: ' + e.sourceURL + ' at line: ' + e.line + ' and column: ' + e.column;
+			const errorMessage = 'Run-time error occured in file: ' + e.sourceURL + ' at line: ' + e.line + ' and column: ' + e.column;
 
 			return new Error(errorMessage);
 		}
@@ -472,16 +473,16 @@ export class Binding {
 	private prepareContextForExpression(model: Object, expression: string, newProps: Array<string>) {
 		let parentViewAndIndex: { view: ViewBase; index: number };
 		let parentView;
-		let addedProps = newProps || [];
+		const addedProps = newProps || [];
 		let expressionCP = expression;
 		if (expressionCP.indexOf(bc.bindingValueKey) > -1) {
 			model[bc.bindingValueKey] = model;
 			addedProps.push(bc.bindingValueKey);
 		}
 
-		let success: boolean = true;
+		let success = true;
 
-		let parentsArray = expressionCP.match(parentsRegex);
+		const parentsArray = expressionCP.match(parentsRegex);
 		if (parentsArray) {
 			for (let i = 0; i < parentsArray.length; i++) {
 				// This prevents later checks to mistake $parents[] for $parent
@@ -509,7 +510,7 @@ export class Binding {
 
 		// For expressions, there are also cases when binding must be updated after component is loaded (e.g. ListView)
 		if (!success) {
-			let targetInstance = this.target.get();
+			const targetInstance = this.target.get();
 			targetInstance.off('loaded', this.loadedHandlerVisualTreeBinding, this);
 			targetInstance.on('loaded', this.loadedHandlerVisualTreeBinding, this);
 		}
@@ -517,9 +518,9 @@ export class Binding {
 
 	private getSourcePropertyValue() {
 		if (this.options.expression) {
-			let changedModel = {};
+			const changedModel = {};
 			changedModel[bc.bindingValueKey] = this.source ? this.source.get() : undefined;
-			let expressionValue = this._getExpressionValue(this.options.expression, false, changedModel);
+			const expressionValue = this._getExpressionValue(this.options.expression, false, changedModel);
 			if (expressionValue instanceof Error) {
 				Trace.write((<Error>expressionValue).message, Trace.categories.Binding, Trace.messageType.error);
 			} else {
@@ -528,7 +529,7 @@ export class Binding {
 		}
 
 		if (this.sourceOptions) {
-			let sourceOptionsInstance = this.sourceOptions.instance.get();
+			const sourceOptionsInstance = this.sourceOptions.instance.get();
 			if (this.sourceOptions.property === bc.bindingValueKey) {
 				return sourceOptionsInstance;
 			} else if (sourceOptionsInstance instanceof Observable && this.sourceOptions.property && this.sourceOptions.property !== '') {
@@ -577,7 +578,7 @@ export class Binding {
 		let index = null;
 		if (property.indexOf(bc.parentsValueKey) === 0) {
 			result = target.parent;
-			let indexParams = paramsRegex.exec(property);
+			const indexParams = paramsRegex.exec(property);
 			if (indexParams && indexParams.length > 1) {
 				index = indexParams[2];
 			}
@@ -599,10 +600,10 @@ export class Binding {
 	}
 
 	private resolveOptions(obj: Object, properties: Array<string>): { instance: WeakRef<Object>; property: any } {
-		let objectsAndProperties = this.resolveObjectsAndProperties(obj, properties);
+		const objectsAndProperties = this.resolveObjectsAndProperties(obj, properties);
 		if (objectsAndProperties.length > 0) {
-			let resolvedObj = objectsAndProperties[objectsAndProperties.length - 1].instance;
-			let prop = objectsAndProperties[objectsAndProperties.length - 1].property;
+			const resolvedObj = objectsAndProperties[objectsAndProperties.length - 1].instance;
+			const prop = objectsAndProperties[objectsAndProperties.length - 1].property;
 
 			return {
 				instance: new WeakRef(this.sourceAsObject(resolvedObj)),

packages/core/ui/core/control-state-change/index.ios.ts

@@ -18,7 +18,7 @@ class ObserverClass extends NSObject {
 export class ControlStateChangeListener implements ControlStateChangeListenerDefinition {
 	private _observer: NSObject;
 	private _control: UIControl;
-	private _observing: boolean = false;
+	private _observing = false;
 
 	private _callback: (state: string) => void;
 

packages/core/ui/core/properties/index.ts

@@ -48,16 +48,16 @@ export interface CssAnimationPropertyOptions<T, U> {
 	readonly valueConverter?: (value: string) => U;
 }
 
-let cssPropertyNames: string[] = [];
-let symbolPropertyMap = {};
-let cssSymbolPropertyMap = {};
+const cssPropertyNames: string[] = [];
+const symbolPropertyMap = {};
+const cssSymbolPropertyMap = {};
 
-let inheritableProperties = new Array<InheritedProperty<any, any>>();
-let inheritableCssProperties = new Array<InheritedCssProperty<any, any>>();
+const inheritableProperties = new Array<InheritedProperty<any, any>>();
+const inheritableCssProperties = new Array<InheritedCssProperty<any, any>>();
 
 function print(map) {
-	let symbols = Object.getOwnPropertySymbols(map);
-	for (let symbol of symbols) {
+	const symbols = Object.getOwnPropertySymbols(map);
+	for (const symbol of symbols) {
 		const prop = map[symbol];
 		if (!prop.registered) {
 			console.log(`Property ${prop.name} not Registered!!!!!`);
@@ -183,8 +183,8 @@ export class Property<T extends ViewBase, U> implements TypedPropertyDescriptor<
 
 	public get: () => U;
 	public set: (value: U) => void;
-	public enumerable: boolean = true;
-	public configurable: boolean = true;
+	public enumerable = true;
+	public configurable = true;
 
 	constructor(options: PropertyOptions<T, U>) {
 		const propertyName = options.name;
@@ -193,10 +193,10 @@ export class Property<T extends ViewBase, U> implements TypedPropertyDescriptor<
 		const key = Symbol(propertyName + ':propertyKey');
 		this.key = key;
 
-		const getDefault: symbol = Symbol(propertyName + ':getDefault');
+		const getDefault = Symbol(propertyName + ':getDefault');
 		this.getDefault = getDefault;
 
-		const setNative: symbol = Symbol(propertyName + ':setNative');
+		const setNative = Symbol(propertyName + ':setNative');
 		this.setNative = setNative;
 
 		const defaultValueKey = Symbol(propertyName + ':nativeDefaultValue');
@@ -1062,8 +1062,8 @@ export class InheritedCssProperty<T extends Style, U> extends CssProperty<T, U>
 				let unsetNativeValue = false;
 				if (reset) {
 					// If unsetValue - we want to reset this property.
-					let parent = view.parent;
-					let style = parent ? parent.style : null;
+					const parent = view.parent;
+					const style = parent ? parent.style : null;
 					// If we have parent and it has non-default value we use as our inherited value.
 					if (style && style[sourceKey] > ValueSource.Default) {
 						value = style[propertyName];
@@ -1192,7 +1192,7 @@ export class ShorthandProperty<T extends Style, P> implements ShorthandProperty<
 			}
 
 			view._batchUpdate(() => {
-				for (let [p, v] of converter(value)) {
+				for (const [p, v] of converter(value)) {
 					this[p.name] = v;
 				}
 			});
@@ -1207,7 +1207,7 @@ export class ShorthandProperty<T extends Style, P> implements ShorthandProperty<
 			}
 
 			view._batchUpdate(() => {
-				for (let [p, v] of converter(value)) {
+				for (const [p, v] of converter(value)) {
 					this[p.cssName] = v;
 				}
 			});
@@ -1261,7 +1261,7 @@ function inheritablePropertyValuesOn(view: ViewBase): Array<{ property: Inherite
 		property: InheritedProperty<any, any>;
 		value: any;
 	}>();
-	for (let prop of inheritableProperties) {
+	for (const prop of inheritableProperties) {
 		const sourceKey = prop.sourceKey;
 		const valueSource: number = view[sourceKey] || ValueSource.Default;
 		if (valueSource !== ValueSource.Default) {
@@ -1279,7 +1279,7 @@ function inheritableCssPropertyValuesOn(style: Style): Array<{ property: Inherit
 		property: InheritedCssProperty<any, any>;
 		value: any;
 	}>();
-	for (let prop of inheritableCssProperties) {
+	for (const prop of inheritableCssProperties) {
 		const sourceKey = prop.sourceKey;
 		const valueSource: number = style[sourceKey] || ValueSource.Default;
 		if (valueSource !== ValueSource.Default) {
@@ -1307,7 +1307,7 @@ export const initNativeView = profile('"properties".initNativeView', function in
 export function applyPendingNativeSetters(view: ViewBase): void {
 	// TODO: Check what happens if a view was suspended and its value was reset, or set back to default!
 	const suspendedUpdates = view._suspendedUpdates;
-	for (let propertyName in suspendedUpdates) {
+	for (const propertyName in suspendedUpdates) {
 		const property = <PropertyInterface>suspendedUpdates[propertyName];
 		const setNative = property.setNative;
 		if (view[setNative]) {
@@ -1341,7 +1341,7 @@ export function applyPendingNativeSetters(view: ViewBase): void {
 
 export function applyAllNativeSetters(view: ViewBase): void {
 	let symbols = Object.getOwnPropertySymbols(view);
-	for (let symbol of symbols) {
+	for (const symbol of symbols) {
 		const property: Property<any, any> = symbolPropertyMap[symbol];
 		if (!property) {
 			continue;
@@ -1362,7 +1362,7 @@ export function applyAllNativeSetters(view: ViewBase): void {
 
 	const style = view.style;
 	symbols = Object.getOwnPropertySymbols(style);
-	for (let symbol of symbols) {
+	for (const symbol of symbols) {
 		const property: CssProperty<any, any> = cssSymbolPropertyMap[symbol];
 		if (!property) {
 			continue;
@@ -1382,7 +1382,7 @@ export function applyAllNativeSetters(view: ViewBase): void {
 
 export function resetNativeView(view: ViewBase): void {
 	let symbols = Object.getOwnPropertySymbols(view);
-	for (let symbol of symbols) {
+	for (const symbol of symbols) {
 		const property: Property<any, any> = symbolPropertyMap[symbol];
 		if (!property) {
 			continue;
@@ -1401,7 +1401,7 @@ export function resetNativeView(view: ViewBase): void {
 	const style = view.style;
 
 	symbols = Object.getOwnPropertySymbols(style);
-	for (let symbol of symbols) {
+	for (const symbol of symbols) {
 		const property: CssProperty<any, any> = cssSymbolPropertyMap[symbol];
 		if (!property) {
 			continue;
@@ -1419,7 +1419,7 @@ export function resetNativeView(view: ViewBase): void {
 }
 
 export function clearInheritedProperties(view: ViewBase): void {
-	for (let prop of inheritableProperties) {
+	for (const prop of inheritableProperties) {
 		const sourceKey = prop.sourceKey;
 		if (view[sourceKey] === ValueSource.Inherited) {
 			prop.set.call(view, unsetValue);
@@ -1427,7 +1427,7 @@ export function clearInheritedProperties(view: ViewBase): void {
 	}
 
 	const style = view.style;
-	for (let prop of inheritableCssProperties) {
+	for (const prop of inheritableCssProperties) {
 		const sourceKey = prop.sourceKey;
 		if (style[sourceKey] === ValueSource.Inherited) {
 			prop.setInheritedValue.call(style, unsetValue);
@@ -1436,8 +1436,8 @@ export function clearInheritedProperties(view: ViewBase): void {
 }
 
 export function resetCSSProperties(style: Style): void {
-	let symbols = Object.getOwnPropertySymbols(style);
-	for (let symbol of symbols) {
+	const symbols = Object.getOwnPropertySymbols(style);
+	for (const symbol of symbols) {
 		let cssProperty;
 		if ((cssProperty = cssSymbolPropertyMap[symbol])) {
 			style[cssProperty.cssName] = unsetValue;
@@ -1450,7 +1450,7 @@ export function resetCSSProperties(style: Style): void {
 
 export function propagateInheritableProperties(view: ViewBase, child: ViewBase): void {
 	const inheritablePropertyValues = inheritablePropertyValuesOn(view);
-	for (let pair of inheritablePropertyValues) {
+	for (const pair of inheritablePropertyValues) {
 		const prop = pair.property;
 		const sourceKey = prop.sourceKey;
 		const currentValueSource: number = child[sourceKey] || ValueSource.Default;
@@ -1462,7 +1462,7 @@ export function propagateInheritableProperties(view: ViewBase, child: ViewBase):
 
 export function propagateInheritableCssProperties(parentStyle: Style, childStyle: Style): void {
 	const inheritableCssPropertyValues = inheritableCssPropertyValuesOn(parentStyle);
-	for (let pair of inheritableCssPropertyValues) {
+	for (const pair of inheritableCssPropertyValues) {
 		const prop = pair.property;
 		const sourceKey = prop.sourceKey;
 		const currentValueSource: number = childStyle[sourceKey] || ValueSource.Default;
@@ -1496,8 +1496,8 @@ export function getSetProperties(view: ViewBase): [string, any][] {
 		result.push([prop, view[prop]]);
 	});
 
-	let symbols = Object.getOwnPropertySymbols(view);
-	for (let symbol of symbols) {
+	const symbols = Object.getOwnPropertySymbols(view);
+	for (const symbol of symbols) {
 		const property = symbolPropertyMap[symbol];
 		if (!property) {
 			continue;
@@ -1513,7 +1513,7 @@ export function getSetProperties(view: ViewBase): [string, any][] {
 export function getComputedCssValues(view: ViewBase): [string, any][] {
 	const result = [];
 	const style = view.style;
-	for (let prop of cssPropertyNames) {
+	for (const prop of cssPropertyNames) {
 		result.push([prop, style[prop]]);
 	}
 

packages/core/ui/core/view-base/index.ts

@@ -36,7 +36,7 @@ function ensureStyleScopeModule() {
 	}
 }
 
-let defaultBindingSource = {};
+const defaultBindingSource = {};
 
 export interface ShowModalOptions {
 	/**
@@ -47,7 +47,7 @@ export interface ShowModalOptions {
 	/**
 	 * A function that will be called when the view is closed. Any arguments provided when calling ShownModallyData.closeCallback will be available here.
 	 */
-	closeCallback: Function;
+	closeCallback: (...args)=>void;
 
 	/**
 	 * An optional parameter specifying whether to show the modal view in full-screen mode.
@@ -94,7 +94,7 @@ export interface ShowModalOptions {
 	cancelable?: boolean;
 }
 
-export function getAncestor(view: ViewBaseDefinition, criterion: string | Function): ViewBaseDefinition {
+export function getAncestor(view: ViewBaseDefinition, criterion: string | { new() }): ViewBaseDefinition {
 	let matcher: (view: ViewBaseDefinition) => boolean = null;
 	if (typeof criterion === 'string') {
 		matcher = (view: ViewBaseDefinition) => view.typeName === criterion;
@@ -143,7 +143,7 @@ export function eachDescendant(view: ViewBaseDefinition, callback: (child: ViewB
 	}
 
 	let continueIteration: boolean;
-	let localCallback = function (child: ViewBaseDefinition): boolean {
+	const localCallback = function (child: ViewBaseDefinition): boolean {
 		continueIteration = callback(child);
 		if (continueIteration) {
 			child.eachChild(localCallback);
@@ -216,8 +216,8 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition
 	public static unloadedEvent = 'unloaded';
 	public static createdEvent = 'created';
 
-	private _onLoadedCalled: boolean = false;
-	private _onUnloadedCalled: boolean = false;
+	private _onLoadedCalled = false;
+	private _onUnloadedCalled = false;
 	private _iosView: Object;
 	private _androidView: Object;
 	private _style: Style;
@@ -532,7 +532,7 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition
 
 	@profile
 	public addPseudoClass(name: string): void {
-		let allStates = this.getAllAliasedStates(name);
+		const allStates = this.getAllAliasedStates(name);
 		for (let i = 0; i < allStates.length; i++) {
 			if (!this.cssPseudoClasses.has(allStates[i])) {
 				this.cssPseudoClasses.add(allStates[i]);
@@ -543,7 +543,7 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition
 
 	@profile
 	public deletePseudoClass(name: string): void {
-		let allStates = this.getAllAliasedStates(name);
+		const allStates = this.getAllAliasedStates(name);
 		for (let i = 0; i < allStates.length; i++) {
 			if (this.cssPseudoClasses.has(allStates[i])) {
 				this.cssPseudoClasses.delete(allStates[i]);
@@ -1004,7 +1004,7 @@ export abstract class ViewBase extends Observable implements ViewBaseDefinition
 		} else {
 			str += `(${this._domId})`;
 		}
-		let source = Source.get(this);
+		const source = Source.get(this);
 		if (source) {
 			str += `@${source};`;
 		}

packages/core/ui/core/view/index.d.ts

@@ -510,14 +510,6 @@ export abstract class View extends ViewBase {
 
 	public getGestureObservers(type: GestureTypes): Array<GesturesObserver>;
 
-	/**
-	 * A basic method signature to hook an event listener (shortcut alias to the addEventListener method).
-	 * @param eventNames - String corresponding to events (e.g. "propertyChange"). Optionally could be used more events separated by `,` (e.g. "propertyChange", "change") or you can use gesture types.
-	 * @param callback - Callback function which will be executed when event is raised.
-	 * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
-	 */
-	on(eventNames: string | GestureTypes, callback: (args: EventData) => void, thisArg?: any);
-
 	/**
 	 * Removes listener(s) for the specified event name.
 	 * @param eventNames Comma delimited names of the events or gesture types the specified listener is associated with.
@@ -526,6 +518,14 @@ export abstract class View extends ViewBase {
 	 */
 	off(eventNames: string | GestureTypes, callback?: (args: EventData) => void, thisArg?: any);
 
+	/**
+	 * A basic method signature to hook an event listener (shortcut alias to the addEventListener method).
+	 * @param eventNames - String corresponding to events (e.g. "propertyChange"). Optionally could be used more events separated by `,` (e.g. "propertyChange", "change") or you can use gesture types.
+	 * @param callback - Callback function which will be executed when event is raised.
+	 * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
+	 */
+	on(eventNames: string | GestureTypes, callback: (args: EventData) => void, thisArg?: any);
+
 	/**
 	 * Raised when a loaded event occurs.
 	 */

packages/core/ui/core/view/index.ios.ts

@@ -69,8 +69,8 @@ export class View extends ViewCommon implements ViewDefinition {
 	}
 
 	public measure(widthMeasureSpec: number, heightMeasureSpec: number): void {
-		let measureSpecsChanged = this._setCurrentMeasureSpecs(widthMeasureSpec, heightMeasureSpec);
-		let forceLayout = (this._privateFlags & PFLAG_FORCE_LAYOUT) === PFLAG_FORCE_LAYOUT;
+		const measureSpecsChanged = this._setCurrentMeasureSpecs(widthMeasureSpec, heightMeasureSpec);
+		const forceLayout = (this._privateFlags & PFLAG_FORCE_LAYOUT) === PFLAG_FORCE_LAYOUT;
 		if (forceLayout || measureSpecsChanged) {
 			// first clears the measured dimension flag
 			this._privateFlags &= ~PFLAG_MEASURED_DIMENSION_SET;
@@ -156,7 +156,7 @@ export class View extends ViewCommon implements ViewDefinition {
 	}
 
 	public _setNativeViewFrame(nativeView: UIView, frame: CGRect): void {
-		let oldFrame = this._cachedFrame || nativeView.frame;
+		const oldFrame = this._cachedFrame || nativeView.frame;
 		if (!CGRectEqualToRect(oldFrame, frame)) {
 			if (Trace.isEnabled()) {
 				Trace.write(this + ' :_setNativeViewFrame: ' + JSON.stringify(IOSHelper.getPositionFromFrame(frame)), Trace.categories.Layout);
@@ -274,7 +274,7 @@ export class View extends ViewCommon implements ViewDefinition {
 
 	public getSafeAreaInsets(): { left; top; right; bottom } {
 		const safeAreaInsets = this.nativeViewProtected && this.nativeViewProtected.safeAreaInsets;
-		let insets = { left: 0, top: 0, right: 0, bottom: 0 };
+		const insets = { left: 0, top: 0, right: 0, bottom: 0 };
 
 		if (safeAreaInsets) {
 			insets.left = layout.round(layout.toDevicePixels(safeAreaInsets.left));
@@ -443,9 +443,9 @@ export class View extends ViewCommon implements ViewDefinition {
 				controller.preferredContentSize = CGSizeMake(options.ios.width, options.ios.height);
 			} else {
 				//use CSS & attribute width & height if option is not provided
-				let handler = () => {
-					let w = <number>(this.width || this.style.width);
-					let h = <number>(this.height || this.style.height);
+				const handler = () => {
+					const w = <number>(this.width || this.style.width);
+					const h = <number>(this.height || this.style.height);
 
 					//TODO: only numeric value is supported, percentage value is not supported like Android
 					if (w > 0 && h > 0) {
@@ -585,8 +585,8 @@ export class View extends ViewCommon implements ViewDefinition {
 		return this.nativeViewProtected.alpha;
 	}
 	[opacityProperty.setNative](value: number) {
-		let nativeView = this.nativeViewProtected;
-		let updateSuspended = this._isPresentationLayerUpdateSuspeneded();
+		const nativeView = this.nativeViewProtected;
+		const updateSuspended = this._isPresentationLayerUpdateSuspeneded();
 		if (!updateSuspended) {
 			CATransaction.begin();
 		}
@@ -693,7 +693,7 @@ export class View extends ViewCommon implements ViewDefinition {
 	}
 
 	_redrawNativeBackground(value: UIColor | Background): void {
-		let updateSuspended = this._isPresentationLayerUpdateSuspeneded();
+		const updateSuspended = this._isPresentationLayerUpdateSuspeneded();
 		if (!updateSuspended) {
 			CATransaction.begin();
 		}

packages/core/ui/core/view/view-common.ts

@@ -49,8 +49,8 @@ export function PseudoClassHandler(...pseudoClasses: string[]): MethodDecorator
 
 	return <T>(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<T>) => {
 		function update(change: number) {
-			let prev = this[listeners] || 0;
-			let next = prev + change;
+			const prev = this[listeners] || 0;
+			const next = prev + change;
 			if (prev <= 0 && next > 0) {
 				this[propertyKey](true);
 			} else if (prev > 0 && next <= 0) {
@@ -242,15 +242,15 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 		if (typeof arg === 'string') {
 			arg = getEventOrGestureName(arg);
 
-			let gesture = gestureFromString(arg);
+			const gesture = gestureFromString(arg);
 			if (gesture && !this._isEvent(arg)) {
 				this._observe(gesture, callback, thisArg);
 			} else {
-				let events = arg.split(',');
+				const events = arg.split(',');
 				if (events.length > 0) {
 					for (let i = 0; i < events.length; i++) {
-						let evt = events[i].trim();
-						let gst = gestureFromString(evt);
+						const evt = events[i].trim();
+						const gst = gestureFromString(evt);
 						if (gst && !this._isEvent(arg)) {
 							this._observe(gst, callback, thisArg);
 						} else {
@@ -268,15 +268,15 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 
 	public removeEventListener(arg: string | GestureTypes, callback?: any, thisArg?: any) {
 		if (typeof arg === 'string') {
-			let gesture = gestureFromString(arg);
+			const gesture = gestureFromString(arg);
 			if (gesture && !this._isEvent(arg)) {
 				this._disconnectGestureObservers(gesture);
 			} else {
-				let events = arg.split(',');
+				const events = arg.split(',');
 				if (events.length > 0) {
 					for (let i = 0; i < events.length; i++) {
-						let evt = events[i].trim();
-						let gst = gestureFromString(evt);
+						const evt = events[i].trim();
+						const gst = gestureFromString(evt);
 						if (gst && !this._isEvent(arg)) {
 							this._disconnectGestureObservers(gst);
 						} else {
@@ -300,7 +300,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 		return undefined;
 	}
 
-	private getModalOptions(args: IArguments): { view: ViewCommon; options: ShowModalOptions } {
+	private getModalOptions(args: any[]): { view: ViewCommon; options: ShowModalOptions } {
 		if (args.length === 0) {
 			throw new Error('showModal without parameters is deprecated. Please call showModal on a view instance instead.');
 		} else {
@@ -333,8 +333,8 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 		}
 	}
 
-	public showModal(): ViewDefinition {
-		const { view, options } = this.getModalOptions(arguments);
+	public showModal(...args): ViewDefinition {
+		const { view, options } = this.getModalOptions(args);
 
 		view._showNativeModalView(this, options);
 
@@ -342,11 +342,11 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	}
 
 	public closeModal(...args) {
-		let closeCallback = this._closeModalCallback;
+		const closeCallback = this._closeModalCallback;
 		if (closeCallback) {
-			closeCallback.apply(undefined, arguments);
+			closeCallback(...args);
 		} else {
-			let parent = this.parent;
+			const parent = this.parent;
 			if (parent) {
 				parent.closeModal(...args);
 			}
@@ -424,7 +424,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	}
 
 	private _disconnectGestureObservers(type: GestureTypes): void {
-		let observers = this.getGestureObservers(type);
+		const observers = this.getGestureObservers(type);
 		if (observers) {
 			for (let i = 0; i < observers.length; i++) {
 				observers[i].disconnect();
@@ -829,7 +829,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 		return ViewHelper.combineMeasuredStates(curState, newState);
 	}
 
-	public static layoutChild(parent: ViewDefinition, child: ViewDefinition, left: number, top: number, right: number, bottom: number, setFrame: boolean = true): void {
+	public static layoutChild(parent: ViewDefinition, child: ViewDefinition, left: number, top: number, right: number, bottom: number, setFrame = true): void {
 		ViewHelper.layoutChild(parent, child, left, top, right, bottom);
 	}
 
@@ -838,7 +838,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	}
 
 	_setCurrentMeasureSpecs(widthMeasureSpec: number, heightMeasureSpec: number): boolean {
-		let changed: boolean = this._currentWidthMeasureSpec !== widthMeasureSpec || this._currentHeightMeasureSpec !== heightMeasureSpec;
+		const changed: boolean = this._currentWidthMeasureSpec !== widthMeasureSpec || this._currentHeightMeasureSpec !== heightMeasureSpec;
 		this._currentWidthMeasureSpec = widthMeasureSpec;
 		this._currentHeightMeasureSpec = heightMeasureSpec;
 
@@ -859,8 +859,8 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	 */
 	_setCurrentLayoutBounds(left: number, top: number, right: number, bottom: number): { boundsChanged: boolean; sizeChanged: boolean } {
 		this._isLayoutValid = true;
-		let boundsChanged: boolean = this._oldLeft !== left || this._oldTop !== top || this._oldRight !== right || this._oldBottom !== bottom;
-		let sizeChanged: boolean = this._oldRight - this._oldLeft !== right - left || this._oldBottom - this._oldTop !== bottom - top;
+		const boundsChanged: boolean = this._oldLeft !== left || this._oldTop !== top || this._oldRight !== right || this._oldBottom !== bottom;
+		const sizeChanged: boolean = this._oldRight - this._oldLeft !== right - left || this._oldBottom - this._oldTop !== bottom - top;
 		this._oldLeft = left;
 		this._oldTop = top;
 		this._oldRight = right;
@@ -906,7 +906,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	}
 
 	public getActualSize(): Size {
-		let currentBounds = this._getCurrentLayoutBounds();
+		const currentBounds = this._getCurrentLayoutBounds();
 		if (!currentBounds) {
 			return undefined;
 		}
@@ -1000,7 +1000,7 @@ export abstract class ViewCommon extends ViewBase implements ViewDefinition {
 	}
 
 	_hasAncestorView(ancestorView: ViewDefinition): boolean {
-		let matcher = (view: ViewDefinition) => view === ancestorView;
+		const matcher = (view: ViewDefinition) => view === ancestorView;
 
 		for (let parent = this.parent; parent != null; parent = parent.parent) {
 			if (matcher(<ViewDefinition>parent)) {

packages/core/ui/core/view/view-helper/view-helper-common.ts

@@ -42,12 +42,12 @@ export class ViewHelper {
 		return { measuredWidth: measureWidth, measuredHeight: measureHeight };
 	}
 
-	public static layoutChild(parent: ViewDefinition, child: ViewDefinition, left: number, top: number, right: number, bottom: number, setFrame: boolean = true): void {
+	public static layoutChild(parent: ViewDefinition, child: ViewDefinition, left: number, top: number, right: number, bottom: number, setFrame = true): void {
 		if (!child || child.isCollapsed) {
 			return;
 		}
 
-		let childStyle = child.style;
+		const childStyle = child.style;
 
 		let childTop: number;
 		let childLeft: number;
@@ -55,8 +55,8 @@ export class ViewHelper {
 		let childWidth = child.getMeasuredWidth();
 		let childHeight = child.getMeasuredHeight();
 
-		let effectiveMarginTop = child.effectiveMarginTop;
-		let effectiveMarginBottom = child.effectiveMarginBottom;
+		const effectiveMarginTop = child.effectiveMarginTop;
+		const effectiveMarginBottom = child.effectiveMarginBottom;
 
 		let vAlignment: VerticalAlignmentDefinition;
 		if (child.effectiveHeight >= 0 && childStyle.verticalAlignment === 'stretch') {
@@ -85,8 +85,8 @@ export class ViewHelper {
 				break;
 		}
 
-		let effectiveMarginLeft = child.effectiveMarginLeft;
-		let effectiveMarginRight = child.effectiveMarginRight;
+		const effectiveMarginLeft = child.effectiveMarginLeft;
+		const effectiveMarginRight = child.effectiveMarginRight;
 
 		let hAlignment: HorizontalAlignmentDefinition;
 		// if (child.effectiveWidth >= 0 && childStyle.horizontalAlignment === 'stretch') {
@@ -115,8 +115,8 @@ export class ViewHelper {
 				break;
 		}
 
-		let childRight = Math.round(childLeft + childWidth);
-		let childBottom = Math.round(childTop + childHeight);
+		const childRight = Math.round(childLeft + childWidth);
+		const childBottom = Math.round(childTop + childHeight);
 		childLeft = Math.round(childLeft);
 		childTop = Math.round(childTop);
 

packages/core/ui/core/weak-event-listener/index.ts

@@ -81,7 +81,7 @@ function validateArgs(source: Observable, eventName: string, handler: (eventData
 export function addWeakEventListener(source: Observable, eventName: string, handler: (eventData: EventData) => void, target: any) {
 	validateArgs(source, eventName, handler, target);
 
-	let shouldAttach: boolean = false;
+	let shouldAttach = false;
 
 	let sourceEventMap = sourcesMap.get(source);
 	if (!sourceEventMap) {

packages/core/ui/dialogs/dialogs-common.ts

@@ -178,65 +178,65 @@ export interface LoginOptions extends ConfirmOptions {
 /**
  * Defines the input type for prompt dialog.
  */
-export module inputType {
+export namespace inputType {
 	/**
 	 * Plain text input type.
 	 */
-	export const text: string = 'text';
+	export const text = 'text';
 
 	/**
 	 * Password input type.
 	 */
-	export const password: string = 'password';
+	export const password = 'password';
 
 	/**
 	 * Email input type.
 	 */
-	export const email: string = 'email';
+	export const email = 'email';
 
 	/**
 	 * Number input type
 	 */
-	export const number: string = 'number';
+	export const number = 'number';
 
 	/**
 	 * Decimal input type
 	 */
-	export const decimal: string = 'decimal';
+	export const decimal = 'decimal';
 
 	/**
 	 * Phone input type
 	 */
-	export const phone: string = 'phone';
+	export const phone = 'phone';
 }
 
 /**
  * Defines the capitalization type for prompt dialog.
  */
-export module capitalizationType {
+export namespace capitalizationType {
 	/**
 	 * No automatic capitalization.
 	 */
-	export const none: string = 'none';
+	export const none = 'none';
 
 	/**
 	 * Capitalizes every character.
 	 */
-	export const all: string = 'all';
+	export const all = 'all';
 
 	/**
 	 * Capitalize the first word of each sentence.
 	 */
-	export const sentences: string = 'sentences';
+	export const sentences = 'sentences';
 
 	/**
 	 * Capitalize the first letter of every word.
 	 */
-	export const words: string = 'words';
+	export const words = 'words';
 }
 
 export function getCurrentPage(): Page {
-	let topmostFrame = Frame.topmost();
+	const topmostFrame = Frame.topmost();
 	if (topmostFrame) {
 		return topmostFrame.currentPage;
 	}
@@ -245,9 +245,9 @@ export function getCurrentPage(): Page {
 }
 
 function applySelectors<T extends View>(view: T, callback: (view: T) => void) {
-	let currentPage = getCurrentPage();
+	const currentPage = getCurrentPage();
 	if (currentPage) {
-		let styleScope = currentPage._styleScope;
+		const styleScope = currentPage._styleScope;
 		if (styleScope) {
 			view._inheritStyleScope(styleScope);
 			view.onLoaded();
@@ -263,6 +263,7 @@ let textField: View;
 
 export function getButtonColors(): { color: Color; backgroundColor: Color } {
 	if (!button) {
+		// eslint-disable-next-line @typescript-eslint/no-var-requires
 		const Button = require('../button').Button;
 		button = new Button();
 		if (global.isIOS) {
@@ -282,6 +283,7 @@ export function getButtonColors(): { color: Color; backgroundColor: Color } {
 
 export function getLabelColor(): Color {
 	if (!label) {
+		// eslint-disable-next-line @typescript-eslint/no-var-requires
 		const Label = require('../label').Label;
 		label = new Label();
 		if (global.isIOS) {
@@ -299,6 +301,7 @@ export function getLabelColor(): Color {
 
 export function getTextFieldColor(): Color {
 	if (!textField) {
+		// eslint-disable-next-line @typescript-eslint/no-var-requires
 		const TextField = require('../text-field').TextField;
 		textField = new TextField();
 		if (global.isIOS) {
@@ -324,7 +327,7 @@ export function parseLoginOptions(args: any[]): LoginOptions {
 		return args[0];
 	}
 
-	let options: LoginOptions = {
+	const options: LoginOptions = {
 		title: DialogStrings.LOGIN,
 		okButtonText: DialogStrings.OK,
 		cancelButtonText: DialogStrings.CANCEL,

packages/core/ui/dialogs/index.android.ts

@@ -44,12 +44,12 @@ function showDialog(builder: android.app.AlertDialog.Builder) {
 		}
 	}
 
-	let { color, backgroundColor } = getButtonColors();
+	const { color, backgroundColor } = getButtonColors();
 
 	if (color) {
-		let buttons: android.widget.Button[] = [];
+		const buttons: android.widget.Button[] = [];
 		for (let i = 0; i < 3; i++) {
-			let id = dlg
+			const id = dlg
 				.getContext()
 				.getResources()
 				.getIdentifier('android:id/button' + i, null, null);
@@ -173,7 +173,7 @@ export function confirm(arg: any): Promise<boolean> {
 	});
 }
 
-export function prompt(arg: any): Promise<PromptResult> {
+export function prompt(...args): Promise<PromptResult> {
 	let options: PromptOptions;
 
 	const defaultOptions = {
@@ -182,19 +182,19 @@ export function prompt(arg: any): Promise<PromptResult> {
 		cancelButtonText: DialogStrings.CANCEL,
 		inputType: inputType.text,
 	};
-
-	if (arguments.length === 1) {
+	const arg = args[0];
+	if (args.length === 1) {
 		if (isString(arg)) {
 			options = defaultOptions;
 			options.message = arg;
 		} else {
 			options = arg;
 		}
-	} else if (arguments.length === 2) {
-		if (isString(arguments[0]) && isString(arguments[1])) {
+	} else if (args.length === 2) {
+		if (isString(arg) && isString(args[1])) {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.defaultText = arguments[1];
+			options.message = arg;
+			options.defaultText = args[1];
 		}
 	}
 
@@ -253,7 +253,7 @@ export function prompt(arg: any): Promise<PromptResult> {
 }
 
 export function login(...args: any[]): Promise<LoginResult> {
-	let options: LoginOptions = parseLoginOptions(args);
+	const options: LoginOptions = parseLoginOptions(args);
 
 	return new Promise<LoginResult>((resolve, reject) => {
 		try {
@@ -295,30 +295,30 @@ export function login(...args: any[]): Promise<LoginResult> {
 	});
 }
 
-export function action(arg: any): Promise<string> {
+export function action(...args): Promise<string> {
 	let options: ActionOptions;
 
 	const defaultOptions = { title: null, cancelButtonText: DialogStrings.CANCEL };
 
-	if (arguments.length === 1) {
-		if (isString(arguments[0])) {
+	if (args.length === 1) {
+		if (isString(args[0])) {
 			options = defaultOptions;
-			options.message = arguments[0];
+			options.message = args[0];
 		} else {
-			options = arguments[0];
+			options = args[0];
 		}
-	} else if (arguments.length === 2) {
-		if (isString(arguments[0]) && isString(arguments[1])) {
+	} else if (args.length === 2) {
+		if (isString(args[0]) && isString(args[1])) {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.cancelButtonText = arguments[1];
+			options.message = args[0];
+			options.cancelButtonText = args[1];
 		}
-	} else if (arguments.length === 3) {
-		if (isString(arguments[0]) && isString(arguments[1]) && typeof arguments[2] !== 'undefined') {
+	} else if (args.length === 3) {
+		if (isString(args[0]) && isString(args[1]) && typeof args[2] !== 'undefined') {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.cancelButtonText = arguments[1];
-			options.actions = arguments[2];
+			options.message = args[0];
+			options.cancelButtonText = args[1];
+			options.actions = args[2];
 		}
 	}
 

packages/core/ui/dialogs/index.d.ts

@@ -2,7 +2,7 @@
 /**
  * Defines the input type for prompt dialog.
  */
-export module inputType {
+export namespace inputType {
 	/**
 	 * Plain text input type.
 	 */
@@ -37,7 +37,7 @@ export module inputType {
 /**
  * Defines the capitalization type for prompt dialog.
  */
-export module capitalizationType {
+export namespace capitalizationType {
 	/**
 	 * No automatic capitalization.
 	 */

packages/core/ui/dialogs/index.ios.ts

@@ -63,19 +63,19 @@ function showUIAlertController(alertController: UIAlertController) {
 		alertController.popoverPresentationController.permittedArrowDirections = 0;
 	}
 
-	let color = getButtonColors().color;
+	const color = getButtonColors().color;
 	if (color) {
 		alertController.view.tintColor = color.ios;
 	}
 
-	let lblColor = getLabelColor();
+	const lblColor = getLabelColor();
 	if (lblColor) {
 		if (alertController.title) {
-			let title = NSAttributedString.alloc().initWithStringAttributes(alertController.title, <any>{ [NSForegroundColorAttributeName]: lblColor.ios });
+			const title = NSAttributedString.alloc().initWithStringAttributes(alertController.title, <any>{ [NSForegroundColorAttributeName]: lblColor.ios });
 			alertController.setValueForKey(title, 'attributedTitle');
 		}
 		if (alertController.message) {
-			let message = NSAttributedString.alloc().initWithStringAttributes(alertController.message, <any>{ [NSForegroundColorAttributeName]: lblColor.ios });
+			const message = NSAttributedString.alloc().initWithStringAttributes(alertController.message, <any>{ [NSForegroundColorAttributeName]: lblColor.ios });
 			alertController.setValueForKey(message, 'attributedMessage');
 		}
 	}
@@ -86,8 +86,8 @@ function showUIAlertController(alertController: UIAlertController) {
 export function alert(arg: any): Promise<void> {
 	return new Promise<void>((resolve, reject) => {
 		try {
-			let options = !isDialogOptions(arg) ? { title: DialogStrings.ALERT, okButtonText: DialogStrings.OK, message: arg + '' } : arg;
-			let alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
+			const options = !isDialogOptions(arg) ? { title: DialogStrings.ALERT, okButtonText: DialogStrings.OK, message: arg + '' } : arg;
+			const alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
 
 			addButtonsToAlertController(alertController, options, () => {
 				resolve();
@@ -103,7 +103,7 @@ export function alert(arg: any): Promise<void> {
 export function confirm(arg: any): Promise<boolean> {
 	return new Promise<boolean>((resolve, reject) => {
 		try {
-			let options = !isDialogOptions(arg)
+			const options = !isDialogOptions(arg)
 				? {
 						title: DialogStrings.CONFIRM,
 						okButtonText: DialogStrings.OK,
@@ -111,7 +111,7 @@ export function confirm(arg: any): Promise<boolean> {
 						message: arg + '',
 				  }
 				: arg;
-			let alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
+			const alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
 
 			addButtonsToAlertController(alertController, options, (r) => {
 				resolve(r);
@@ -124,35 +124,34 @@ export function confirm(arg: any): Promise<boolean> {
 	});
 }
 
-export function prompt(arg: any): Promise<PromptResult> {
+export function prompt(...args): Promise<PromptResult> {
 	let options: PromptOptions;
 
-	let defaultOptions = {
+	const defaultOptions = {
 		title: DialogStrings.PROMPT,
 		okButtonText: DialogStrings.OK,
 		cancelButtonText: DialogStrings.CANCEL,
 		inputType: inputType.text,
 	};
-
-	if (arguments.length === 1) {
+	const arg = args[0];
+	if (args.length === 1) {
 		if (isString(arg)) {
 			options = defaultOptions;
 			options.message = arg;
 		} else {
 			options = arg;
 		}
-	} else if (arguments.length === 2) {
-		if (isString(arguments[0]) && isString(arguments[1])) {
+	} else if (args.length === 2) {
+		if (isString(arg) && isString(args[1])) {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.defaultText = arguments[1];
+			options.message = arg;
+			options.defaultText = args[1];
 		}
 	}
 
 	return new Promise<PromptResult>((resolve, reject) => {
 		try {
-			let textField: UITextField;
-			let alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
+			const alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
 
 			alertController.addTextFieldWithConfigurationHandler((arg: UITextField) => {
 				arg.text = isString(options.defaultText) ? options.defaultText : '';
@@ -168,13 +167,13 @@ export function prompt(arg: any): Promise<PromptResult> {
 					arg.keyboardType = UIKeyboardType.PhonePad;
 				}
 
-				let color = getTextFieldColor();
+				const color = getTextFieldColor();
 				if (color) {
 					arg.textColor = arg.tintColor = color.ios;
 				}
 			});
 
-			textField = alertController.textFields.firstObject;
+			const textField: UITextField = alertController.textFields.firstObject;
 
 			if (options) {
 				switch (options.capitalizationType) {
@@ -208,15 +207,13 @@ export function prompt(arg: any): Promise<PromptResult> {
 }
 
 export function login(...args: any[]): Promise<LoginResult> {
-	let options: LoginOptions = parseLoginOptions(args);
+	const options: LoginOptions = parseLoginOptions(args);
 
 	return new Promise<LoginResult>((resolve, reject) => {
 		try {
-			let userNameTextField: UITextField;
-			let passwordTextField: UITextField;
-			let alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
+			const alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.Alert);
 
-			let textFieldColor = getTextFieldColor();
+			const textFieldColor = getTextFieldColor();
 
 			alertController.addTextFieldWithConfigurationHandler((arg: UITextField) => {
 				arg.placeholder = 'Login';
@@ -238,9 +235,8 @@ export function login(...args: any[]): Promise<LoginResult> {
 					arg.textColor = arg.tintColor = textFieldColor.ios;
 				}
 			});
-
-			userNameTextField = alertController.textFields.firstObject;
-			passwordTextField = alertController.textFields.lastObject;
+			const userNameTextField: UITextField = alertController.textFields.firstObject;
+			const passwordTextField: UITextField = alertController.textFields.lastObject;
 
 			addButtonsToAlertController(alertController, options, (r) => {
 				resolve({
@@ -257,30 +253,30 @@ export function login(...args: any[]): Promise<LoginResult> {
 	});
 }
 
-export function action(): Promise<string> {
+export function action(...args): Promise<string> {
 	let options: ActionOptions;
 
-	let defaultOptions = { title: null, cancelButtonText: DialogStrings.CANCEL };
+	const defaultOptions = { title: null, cancelButtonText: DialogStrings.CANCEL };
 
-	if (arguments.length === 1) {
-		if (isString(arguments[0])) {
+	if (args.length === 1) {
+		if (isString(args[0])) {
 			options = defaultOptions;
-			options.message = arguments[0];
+			options.message = args[0];
 		} else {
-			options = arguments[0];
+			options = args[0];
 		}
-	} else if (arguments.length === 2) {
-		if (isString(arguments[0]) && isString(arguments[1])) {
+	} else if (args.length === 2) {
+		if (isString(args[0]) && isString(args[1])) {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.cancelButtonText = arguments[1];
+			options.message = args[0];
+			options.cancelButtonText = args[1];
 		}
-	} else if (arguments.length === 3) {
-		if (isString(arguments[0]) && isString(arguments[1]) && isDefined(arguments[2])) {
+	} else if (args.length === 3) {
+		if (isString(args[0]) && isString(args[1]) && isDefined(args[2])) {
 			options = defaultOptions;
-			options.message = arguments[0];
-			options.cancelButtonText = arguments[1];
-			options.actions = arguments[2];
+			options.message = args[0];
+			options.cancelButtonText = args[1];
+			options.actions = args[2];
 		}
 	}
 
@@ -288,7 +284,7 @@ export function action(): Promise<string> {
 		try {
 			let i: number;
 			let action: string;
-			let alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.ActionSheet);
+			const alertController = UIAlertController.alertControllerWithTitleMessagePreferredStyle(options.title, options.message, UIAlertControllerStyle.ActionSheet);
 
 			if (options.actions) {
 				for (i = 0; i < options.actions.length; i++) {

packages/core/ui/editable-text-base/index.android.ts

@@ -288,7 +288,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[returnKeyTypeProperty.getDefault](): 'done' | 'next' | 'go' | 'search' | 'send' | string {
-		let ime = this.nativeTextViewProtected.getImeOptions();
+		const ime = this.nativeTextViewProtected.getImeOptions();
 		switch (ime) {
 			case android.view.inputmethod.EditorInfo.IME_ACTION_DONE:
 				return 'done';
@@ -327,8 +327,8 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 			case 'send':
 				newImeOptions = android.view.inputmethod.EditorInfo.IME_ACTION_SEND;
 				break;
-			default:
-				let ime = +value;
+			default:{
+				const ime = +value;
 				if (!isNaN(ime)) {
 					newImeOptions = ime;
 				} else {
@@ -336,6 +336,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 				}
 				break;
 			}
+		}
 
 		this.nativeTextViewProtected.setImeOptions(newImeOptions);
 	}
@@ -353,7 +354,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[autocapitalizationTypeProperty.getDefault](): 'none' | 'words' | 'sentences' | 'allcharacters' | string {
-		let inputType = this.nativeTextViewProtected.getInputType();
+		const inputType = this.nativeTextViewProtected.getInputType();
 		if ((inputType & android.text.InputType.TYPE_TEXT_FLAG_CAP_WORDS) === android.text.InputType.TYPE_TEXT_FLAG_CAP_WORDS) {
 			return 'words';
 		} else if ((inputType & android.text.InputType.TYPE_TEXT_FLAG_CAP_SENTENCES) === android.text.InputType.TYPE_TEXT_FLAG_CAP_SENTENCES) {
@@ -381,8 +382,8 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 			case 'allcharacters':
 				inputType = inputType | android.text.InputType.TYPE_TEXT_FLAG_CAP_CHARACTERS; //4096 (0x00010000) 13th bit
 				break;
-			default:
-				let number = +value;
+			default:{
+				const number = +value;
 				// We set the default value.
 				if (!isNaN(number)) {
 					inputType = number;
@@ -391,12 +392,13 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 				}
 				break;
 			}
+		}
 
 		this._setInputType(inputType);
 	}
 
 	[autocorrectProperty.getDefault](): boolean {
-		let autocorrect = this.nativeTextViewProtected.getInputType();
+		const autocorrect = this.nativeTextViewProtected.getInputType();
 		if ((autocorrect & android.text.InputType.TYPE_TEXT_FLAG_AUTO_CORRECT) === android.text.InputType.TYPE_TEXT_FLAG_AUTO_CORRECT) {
 			return true;
 		}

packages/core/ui/editable-text-base/index.ios.ts

@@ -11,7 +11,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[keyboardTypeProperty.getDefault](): 'datetime' | 'phone' | 'number' | 'url' | 'email' | 'integer' | string {
-		let keyboardType = this.nativeTextViewProtected.keyboardType;
+		const keyboardType = this.nativeTextViewProtected.keyboardType;
 		switch (keyboardType) {
 			case UIKeyboardType.NumbersAndPunctuation:
 				return 'number';
@@ -59,7 +59,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 				break;
 
 			default:
-				let kt = +value;
+				const kt = +value;
 				if (!isNaN(kt)) {
 					newKeyboardType = <UIKeyboardType>kt;
 				} else {
@@ -72,7 +72,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[returnKeyTypeProperty.getDefault](): 'done' | 'next' | 'go' | 'search' | 'send' | string {
-		let returnKeyType = this.nativeTextViewProtected.returnKeyType;
+		const returnKeyType = this.nativeTextViewProtected.returnKeyType;
 		switch (returnKeyType) {
 			case UIReturnKeyType.Done:
 				return 'done';
@@ -112,7 +112,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 				newValue = UIReturnKeyType.Send;
 				break;
 			default:
-				let rkt = +value;
+				const rkt = +value;
 				if (!isNaN(rkt)) {
 					newValue = <UIKeyboardType>rkt;
 				} else {
@@ -125,7 +125,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[autocapitalizationTypeProperty.getDefault](): 'none' | 'words' | 'sentences' | 'allcharacters' {
-		let autocapitalizationType = this.nativeTextViewProtected.autocapitalizationType;
+		const autocapitalizationType = this.nativeTextViewProtected.autocapitalizationType;
 		switch (autocapitalizationType) {
 			case UITextAutocapitalizationType.None:
 				return 'none';
@@ -167,7 +167,7 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 	}
 
 	[autocorrectProperty.getDefault](): boolean | number {
-		let autocorrectionType = this.nativeTextViewProtected.autocorrectionType;
+		const autocorrectionType = this.nativeTextViewProtected.autocorrectionType;
 		switch (autocorrectionType) {
 			case UITextAutocorrectionType.Yes:
 				return true;
@@ -192,12 +192,12 @@ export abstract class EditableTextBase extends EditableTextBaseCommon {
 }
 
 export function _updateCharactersInRangeReplacementString(formattedText: FormattedString, rangeLocation: number, rangeLength: number, replacementString: string): void {
-	let deletingText = !replacementString;
+	const deletingText = !replacementString;
 	let currentLocation = 0;
 	for (let i = 0, length = formattedText.spans.length; i < length; i++) {
-		let span = formattedText.spans.getItem(i);
+		const span = formattedText.spans.getItem(i);
 		if (currentLocation <= rangeLocation && rangeLocation < currentLocation + span.text.length) {
-			let newText = splice(span.text, rangeLocation - currentLocation, deletingText ? rangeLength : 0, replacementString);
+			const newText = splice(span.text, rangeLocation - currentLocation, deletingText ? rangeLength : 0, replacementString);
 			span._setTextInternal(newText);
 
 			return;

packages/core/ui/enums/index.ts

@@ -2,7 +2,7 @@
 import * as animationModule from '../../ui/animation';
 
 export type KeyboardType = 'datetime' | 'phone' | 'number' | 'url' | 'email' | 'integer';
-export module KeyboardType {
+export namespace KeyboardType {
 	export const datetime = 'datetime';
 	export const phone = 'phone';
 	export const number = 'number';
@@ -11,7 +11,7 @@ export module KeyboardType {
 	export const integer = 'integer';
 }
 
-export module ReturnKeyType {
+export namespace ReturnKeyType {
 	export const done = 'done';
 	export const next = 'next';
 	export const go = 'go';
@@ -25,154 +25,154 @@ export class TextAlignment {
 	static right = 'right';
 }
 
-export module TextDecoration {
+export namespace TextDecoration {
 	export const none = 'none';
 	export const underline = 'underline';
 	export const lineThrough = 'line-through';
 }
 
-export module TextTransform {
+export namespace TextTransform {
 	export const none = 'none';
 	export const capitalize = 'capitalize';
 	export const uppercase = 'uppercase';
 	export const lowercase = 'lowercase';
 }
 
-export module WhiteSpace {
+export namespace WhiteSpace {
 	export const normal = 'normal';
 	export const nowrap = 'nowrap';
 }
 
-export module Orientation {
+export namespace Orientation {
 	export const horizontal = 'horizontal';
 	export const vertical = 'vertical';
 }
 
-export module DeviceOrientation {
+export namespace DeviceOrientation {
 	export const portrait = 'portrait';
 	export const landscape = 'landscape';
 	export const unknown = 'unknown';
 }
 
-export module HorizontalAlignment {
+export namespace HorizontalAlignment {
 	export const left = 'left';
 	export const center = 'center';
 	export const right = 'right';
 	export const stretch = 'stretch';
 }
 
-export module VerticalAlignment {
+export namespace VerticalAlignment {
 	export const top = 'top';
 	export const middle = 'middle';
 	export const bottom = 'bottom';
 	export const stretch = 'stretch';
 }
 
-export module Stretch {
-	export const none: string = 'none';
-	export const aspectFill: string = 'aspectFill';
-	export const aspectFit: string = 'aspectFit';
-	export const fill: string = 'fill';
+export namespace Stretch {
+	export const none = 'none';
+	export const aspectFill = 'aspectFill';
+	export const aspectFit = 'aspectFit';
+	export const fill = 'fill';
 }
 
-export module Visibility {
-	export const visible: string = 'visible';
-	export const collapse: string = 'collapse';
-	export const collapsed: string = 'collapsed';
-	export const hidden: string = 'hidden';
+export namespace Visibility {
+	export const visible = 'visible';
+	export const collapse = 'collapse';
+	export const collapsed = 'collapsed';
+	export const hidden = 'hidden';
 }
 
-export module FontAttributes {
+export namespace FontAttributes {
 	export const Normal = 0;
 	export const Bold = 1;
 	export const Italic = 1 << 1;
 }
 
-export module DeviceType {
-	export const Phone: string = 'Phone';
-	export const Tablet: string = 'Tablet';
+export namespace DeviceType {
+	export const Phone = 'Phone';
+	export const Tablet = 'Tablet';
 }
 
-export module UpdateTextTrigger {
-	export const focusLost: string = 'focusLost';
-	export const textChanged: string = 'textChanged';
+export namespace UpdateTextTrigger {
+	export const focusLost = 'focusLost';
+	export const textChanged = 'textChanged';
 }
 
-export module Accuracy {
-	export const any: number = 300;
-	export const high: number = 3;
+export namespace Accuracy {
+	export const any = 300;
+	export const high = 3;
 }
 
-export module Dock {
-	export const left: string = 'left';
-	export const top: string = 'top';
-	export const right: string = 'right';
-	export const bottom: string = 'bottom';
+export namespace Dock {
+	export const left = 'left';
+	export const top = 'top';
+	export const right = 'right';
+	export const bottom = 'bottom';
 }
 
-export module AutocapitalizationType {
-	export const none: string = 'none';
-	export const words: string = 'words';
-	export const sentences: string = 'sentences';
-	export const allCharacters: string = 'allcharacters';
+export namespace AutocapitalizationType {
+	export const none = 'none';
+	export const words = 'words';
+	export const sentences = 'sentences';
+	export const allCharacters = 'allcharacters';
 }
 
-export module NavigationBarVisibility {
-	export const auto: string = 'auto';
-	export const never: string = 'never';
-	export const always: string = 'always';
+export namespace NavigationBarVisibility {
+	export const auto = 'auto';
+	export const never = 'never';
+	export const always = 'always';
 }
 
-export module AndroidActionBarIconVisibility {
-	export const auto: string = 'auto';
-	export const never: string = 'never';
-	export const always: string = 'always';
+export namespace AndroidActionBarIconVisibility {
+	export const auto = 'auto';
+	export const never = 'never';
+	export const always = 'always';
 }
 
-export module AndroidActionItemPosition {
-	export const actionBar: string = 'actionBar';
-	export const actionBarIfRoom: string = 'actionBarIfRoom';
-	export const popup: string = 'popup';
+export namespace AndroidActionItemPosition {
+	export const actionBar = 'actionBar';
+	export const actionBarIfRoom = 'actionBarIfRoom';
+	export const popup = 'popup';
 }
 
-export module IOSActionItemPosition {
-	export const left: string = 'left';
-	export const right: string = 'right';
+export namespace IOSActionItemPosition {
+	export const left = 'left';
+	export const right = 'right';
 }
 
-export module ImageFormat {
-	export const png: string = 'png';
-	export const jpeg: string = 'jpeg';
-	export const jpg: string = 'jpg';
+export namespace ImageFormat {
+	export const png = 'png';
+	export const jpeg = 'jpeg';
+	export const jpg = 'jpg';
 }
 
-export module FontStyle {
-	export const normal: string = 'normal';
-	export const italic: string = 'italic';
+export namespace FontStyle {
+	export const normal = 'normal';
+	export const italic = 'italic';
 }
 
-export module FontWeight {
-	export const thin: string = '100';
-	export const extraLight: string = '200';
-	export const light: string = '300';
-	export const normal: string = 'normal'; // 400
-	export const medium: string = '500';
-	export const semiBold: string = '600';
-	export const bold: string = 'bold'; // 700
-	export const extraBold: string = '800';
-	export const black: string = '900';
+export namespace FontWeight {
+	export const thin = '100';
+	export const extraLight = '200';
+	export const light = '300';
+	export const normal = 'normal'; // 400
+	export const medium = '500';
+	export const semiBold = '600';
+	export const bold = 'bold'; // 700
+	export const extraBold = '800';
+	export const black = '900';
 }
 
-export module BackgroundRepeat {
-	export const repeat: string = 'repeat';
-	export const repeatX: string = 'repeat-x';
-	export const repeatY: string = 'repeat-y';
-	export const noRepeat: string = 'no-repeat';
+export namespace BackgroundRepeat {
+	export const repeat = 'repeat';
+	export const repeatX = 'repeat-x';
+	export const repeatY = 'repeat-y';
+	export const noRepeat = 'no-repeat';
 }
 
 let animation: typeof animationModule;
 
-export module AnimationCurve {
+export namespace AnimationCurve {
 	export const ease = 'ease';
 	export const easeIn = 'easeIn';
 	export const easeOut = 'easeOut';
@@ -186,12 +186,12 @@ export module AnimationCurve {
 	}
 }
 
-export module StatusBarStyle {
+export namespace StatusBarStyle {
 	export const light = 'light';
 	export const dark = 'dark';
 }
 
-export module SystemAppearance {
+export namespace SystemAppearance {
 	export const light = 'light';
 	export const dark = 'dark';
 }

packages/core/ui/frame/activity.android.ts

@@ -1,5 +1,6 @@
 import '../../globals';
 import { setActivityCallbacks, AndroidActivityCallbacks } from '.';
+// eslint-disable-next-line @typescript-eslint/no-var-requires
 const appModule = require('../../application');
 
 /**

packages/core/ui/frame/fragment.android.ts

@@ -29,7 +29,7 @@ const FragmentClass = (<any>org.nativescript.widgets.FragmentBase).extend('com.t
 	},
 
 	onCreateView(inflater: android.view.LayoutInflater, container: android.view.ViewGroup, savedInstanceState: android.os.Bundle) {
-		let result = this._callbacks.onCreateView(this, inflater, container, savedInstanceState, superProto.onCreateView);
+		const result = this._callbacks.onCreateView(this, inflater, container, savedInstanceState, superProto.onCreateView);
 
 		return result;
 	},

packages/core/ui/frame/fragment.transitions.ios.ts

@@ -5,7 +5,7 @@ import { FadeTransition } from '../transition/fade-transition';
 
 import { Trace } from '../../trace';
 
-module UIViewControllerAnimatedTransitioningMethods {
+namespace UIViewControllerAnimatedTransitioningMethods {
 	const methodSignature = NSMethodSignature.signatureWithObjCTypes('v@:c');
 	const invocation = NSInvocation.invocationWithMethodSignature(methodSignature);
 	invocation.selector = 'completeTransition:';

packages/core/ui/frame/frame-common.ts

@@ -249,6 +249,12 @@ export class FrameBase extends CustomLayoutView {
 		}
 
 		newPage.onNavigatedTo(isBack);
+		this.notify({
+			eventName: Page.navigatedToEvent,
+			object: this,
+			isBack,
+			entry,
+		});
 
 		// Reset executing context after NavigatedTo is raised;
 		// we do not want to execute two navigations in parallel in case
@@ -282,6 +288,7 @@ export class FrameBase extends CustomLayoutView {
 	}
 
 	private isNestedWithin(parentFrameCandidate: FrameBase): boolean {
+		// eslint-disable-next-line @typescript-eslint/no-this-alias
 		let frameAncestor: FrameBase = this;
 		while (frameAncestor) {
 			frameAncestor = <FrameBase>getAncestor(frameAncestor, FrameBase);
@@ -412,6 +419,13 @@ export class FrameBase extends CustomLayoutView {
 		}
 
 		backstackEntry.resolvedPage.onNavigatingTo(backstackEntry.entry.context, isBack, backstackEntry.entry.bindingContext);
+		this.notify({
+			eventName: Page.navigatingToEvent,
+			object: this,
+			isBack,
+			entry: backstackEntry.entry,
+			fromEntry:this.currentEntry
+		});
 	}
 
 	public get animated(): boolean {
@@ -561,7 +575,7 @@ export class FrameBase extends CustomLayoutView {
 		let i = length - 1;
 		console.log(`Frame Back Stack: `);
 		while (i >= 0) {
-			let backstackEntry = <BackstackEntry>this.backStack[i--];
+			const backstackEntry = <BackstackEntry>this.backStack[i--];
 			console.log(`\t${backstackEntry.resolvedPage}`);
 		}
 	}

packages/core/ui/frame/frame-interfaces.ts

@@ -80,7 +80,7 @@ export interface AndroidActivityCallbacks {
 	onPostResume(activity: any, superFunc: Function): void;
 	onDestroy(activity: any, superFunc: Function): void;
 	onBackPressed(activity: any, superFunc: Function): void;
-	onRequestPermissionsResult(activity: any, requestCode: number, permissions: Array<String>, grantResults: Array<number>, superFunc: Function): void;
+	onRequestPermissionsResult(activity: any, requestCode: number, permissions: Array<string>, grantResults: Array<number>, superFunc: Function): void;
 	onActivityResult(activity: any, requestCode: number, resultCode: number, data: any, superFunc: Function);
 	onNewIntent(activity: any, intent: any, superSetIntentFunc: Function, superFunc: Function): void;
 }

packages/core/ui/frame/frame-stack.ts

@@ -1,7 +1,7 @@
 // Types.
 import { FrameBase } from './frame-common';
 
-export let frameStack: Array<FrameBase> = [];
+export const frameStack: Array<FrameBase> = [];
 
 export function topmost(): FrameBase {
 	if (frameStack.length > 0) {

packages/core/ui/frame/index.android.ts

@@ -40,6 +40,7 @@ let fragmentId = -1;
 export let moduleLoaded: boolean;
 
 if (global && global.__inspector) {
+	// eslint-disable-next-line @typescript-eslint/no-var-requires
 	const devtools = require('../../debugger/devtools-elements');
 	devtools.attachDOMInspectorEventCallbacks(global.__inspector);
 	devtools.attachDOMInspectorCommandCallbacks(global.__inspector);

packages/core/ui/frame/index.d.ts

@@ -1,11 +1,17 @@
 import { NavigationType, FrameBase } from './frame-common';
-import { Page } from '../page';
+import { NavigatedData, Page } from '../page';
 import { Observable, EventData } from '../../data/observable';
 import { View } from '../core/view';
 import { Transition } from '../transition';
 
 export * from './frame-interfaces';
 
+export interface NavigationData extends EventData  {
+	entry?: NavigationEntry;
+	fromEntry?: NavigationEntry;
+	isBack?: boolean;
+}
+
 /**
  * Represents the logical View unit that is responsible for navigation within an application.
  * Nested frames are supported, enabling hierarchical navigation scenarios.
@@ -210,6 +216,16 @@ export class Frame extends FrameBase {
 	 * @param thisArg - An optional parameter which will be used as `this` context for callback execution.
 	 */
 	on(eventNames: string, callback: (args: EventData) => void, thisArg?: any);
+
+	/**
+	 * Raised when navigation to the page has started.
+	 */
+	public on(event: 'navigatingTo', callback: (args: NavigationData) => void, thisArg?: any);
+
+	/**
+	 * Raised when navigation to the page has finished.
+	 */
+	public on(event: 'navigatedTo', callback: (args: NavigationData) => void, thisArg?: any);
 }
 
 /**
@@ -440,7 +456,7 @@ export interface AndroidActivityCallbacks {
 	onPostResume(activity: any, superFunc: Function): void;
 	onDestroy(activity: any, superFunc: Function): void;
 	onBackPressed(activity: any, superFunc: Function): void;
-	onRequestPermissionsResult(activity: any, requestCode: number, permissions: Array<String>, grantResults: Array<number>, superFunc: Function): void;
+	onRequestPermissionsResult(activity: any, requestCode: number, permissions: Array<string>, grantResults: Array<number>, superFunc: Function): void;
 	onActivityResult(activity: any, requestCode: number, resultCode: number, data: any, superFunc: Function);
 	onNewIntent(activity: any, intent: any, superSetIntentFunc: Function, superFunc: Function): void;
 }

packages/core/ui/frame/index.ios.ts

@@ -67,12 +67,12 @@ export class Frame extends FrameBase {
 	public _navigateCore(backstackEntry: any) {
 		super._navigateCore(backstackEntry);
 
-		let viewController: UIViewController = backstackEntry.resolvedPage.ios;
+		const viewController: UIViewController = backstackEntry.resolvedPage.ios;
 		if (!viewController) {
 			throw new Error('Required page does not have a viewController created.');
 		}
 
-		let clearHistory = backstackEntry.entry.clearHistory;
+		const clearHistory = backstackEntry.entry.clearHistory;
 		if (clearHistory) {
 			navDepth = -1;
 		}
@@ -101,7 +101,7 @@ export class Frame extends FrameBase {
 			viewController[TRANSITION] = { name: NON_ANIMATED_TRANSITION };
 		}
 
-		let nativeTransition = _getNativeTransition(navigationTransition, true);
+		const nativeTransition = _getNativeTransition(navigationTransition, true);
 		if (!nativeTransition && navigationTransition) {
 			this._ios.controller.delegate = this._animatedDelegate;
 			viewController[DELEGATE] = this._animatedDelegate;
@@ -116,7 +116,7 @@ export class Frame extends FrameBase {
 		if (!animated && majorVersion > 10) {
 			// Reset back button title before pushing view controller to prevent
 			// displaying default 'back' title (when NavigaitonButton custom title is set).
-			let barButtonItem = UIBarButtonItem.alloc().initWithTitleStyleTargetAction('', UIBarButtonItemStyle.Plain, null, null);
+			const barButtonItem = UIBarButtonItem.alloc().initWithTitleStyleTargetAction('', UIBarButtonItemStyle.Plain, null, null);
 			viewController.navigationItem.backBarButtonItem = barButtonItem;
 		}
 
@@ -155,7 +155,7 @@ export class Frame extends FrameBase {
 		// We should hide the current entry from the back stack.
 		// This is the case for HMR when NavigationType.replace.
 		if (!Frame._isEntryBackstackVisible(this._currentEntry) || isReplace) {
-			let newControllers = NSMutableArray.alloc<UIViewController>().initWithArray(this._ios.controller.viewControllers);
+			const newControllers = NSMutableArray.alloc<UIViewController>().initWithArray(this._ios.controller.viewControllers);
 			if (newControllers.count === 0) {
 				throw new Error('Wrong controllers count.');
 			}
@@ -190,8 +190,8 @@ export class Frame extends FrameBase {
 		super._goBackCore(backstackEntry);
 		navDepth = backstackEntry[NAV_DEPTH];
 
-		let controller = backstackEntry.resolvedPage.ios;
-		let animated = this._currentEntry ? this._getIsAnimatedNavigation(this._currentEntry.entry) : false;
+		const controller = backstackEntry.resolvedPage.ios;
+		const animated = this._currentEntry ? this._getIsAnimatedNavigation(this._currentEntry.entry) : false;
 
 		this._updateActionBar(backstackEntry.resolvedPage);
 		if (Trace.isEnabled()) {
@@ -201,7 +201,7 @@ export class Frame extends FrameBase {
 		this._ios.controller.popToViewControllerAnimated(controller, animated);
 	}
 
-	public _updateActionBar(page?: Page, disableNavBarAnimation: boolean = false): void {
+	public _updateActionBar(page?: Page, disableNavBarAnimation = false): void {
 		super._updateActionBar(page);
 
 		if (page && this.currentPage && this.currentPage.modal === page) {
@@ -209,8 +209,8 @@ export class Frame extends FrameBase {
 		}
 
 		page = page || this.currentPage;
-		let newValue = this._getNavBarVisible(page);
-		let disableNavBarAnimationCache = this._ios._disableNavBarAnimation;
+		const newValue = this._getNavBarVisible(page);
+		const disableNavBarAnimationCache = this._ios._disableNavBarAnimation;
 
 		if (disableNavBarAnimation) {
 			this._ios._disableNavBarAnimation = true;
@@ -249,7 +249,7 @@ export class Frame extends FrameBase {
 					case 'never':
 						return false;
 
-					case 'auto':
+					case 'auto':{
 						let newValue: boolean;
 
 						if (page && page.actionBarHidden !== undefined) {
@@ -264,6 +264,7 @@ export class Frame extends FrameBase {
 					}
 				}
 		}
+	}
 
 	public static get defaultAnimatedNavigation(): boolean {
 		return FrameBase.defaultAnimatedNavigation;
@@ -305,14 +306,14 @@ export class Frame extends FrameBase {
 	}
 }
 
-let transitionDelegates = new Array<TransitionDelegate>();
+const transitionDelegates = new Array<TransitionDelegate>();
 
 @NativeClass
 class TransitionDelegate extends NSObject {
 	private _id: string;
 
 	public static initWithOwnerId(id: string): TransitionDelegate {
-		let delegate = <TransitionDelegate>TransitionDelegate.new();
+		const delegate = <TransitionDelegate>TransitionDelegate.new();
 		delegate._id = id;
 		transitionDelegates.push(delegate);
 
@@ -336,7 +337,7 @@ class TransitionDelegate extends NSObject {
 			}
 		}
 
-		let index = transitionDelegates.indexOf(this);
+		const index = transitionDelegates.indexOf(this);
 		if (index > -1) {
 			transitionDelegates.splice(index, 1);
 		}
@@ -375,7 +376,7 @@ class UINavigationControllerAnimatedDelegate extends NSObject implements UINavig
 			return null;
 		}
 
-		let navigationTransition = <NavigationTransition>viewController[TRANSITION];
+		const navigationTransition = <NavigationTransition>viewController[TRANSITION];
 		if (!navigationTransition) {
 			return null;
 		}
@@ -384,8 +385,8 @@ class UINavigationControllerAnimatedDelegate extends NSObject implements UINavig
 			Trace.write(`UINavigationControllerImpl.navigationControllerAnimationControllerForOperationFromViewControllerToViewController(${operation}, ${fromVC}, ${toVC}), transition: ${JSON.stringify(navigationTransition)}`, Trace.categories.NativeLifecycle);
 		}
 
-		let curve = _getNativeCurve(navigationTransition);
-		let animationController = _createIOSAnimatedTransitioning(navigationTransition, curve, operation, fromVC, toVC);
+		const curve = _getNativeCurve(navigationTransition);
+		const animationController = _createIOSAnimatedTransitioning(navigationTransition, curve, operation, fromVC, toVC);
 
 		return animationController;
 	}
@@ -396,7 +397,7 @@ class UINavigationControllerImpl extends UINavigationController {
 	private _owner: WeakRef<Frame>;
 
 	public static initWithOwner(owner: WeakRef<Frame>): UINavigationControllerImpl {
-		let controller = <UINavigationControllerImpl>UINavigationControllerImpl.new();
+		const controller = <UINavigationControllerImpl>UINavigationControllerImpl.new();
 		controller._owner = owner;
 
 		return controller;
@@ -426,13 +427,13 @@ class UINavigationControllerImpl extends UINavigationController {
 	}
 
 	private animateWithDuration(navigationTransition: NavigationTransition, nativeTransition: UIViewAnimationTransition, transitionType: string, baseCallback: Function): void {
-		let duration = navigationTransition.duration ? navigationTransition.duration / 1000 : _defaultTransitionDuration;
-		let curve = _getNativeCurve(navigationTransition);
+		const duration = navigationTransition.duration ? navigationTransition.duration / 1000 : _defaultTransitionDuration;
+		const curve = _getNativeCurve(navigationTransition);
 
-		let transitionTraced = Trace.isCategorySet(Trace.categories.Transition);
+		const transitionTraced = Trace.isCategorySet(Trace.categories.Transition);
 		let transitionDelegate: TransitionDelegate;
 		if (transitionTraced) {
-			let id = _getTransitionId(nativeTransition, transitionType);
+			const id = _getTransitionId(nativeTransition, transitionType);
 			transitionDelegate = TransitionDelegate.initWithOwnerId(id);
 		}
 
@@ -451,12 +452,12 @@ class UINavigationControllerImpl extends UINavigationController {
 
 	@profile
 	public pushViewControllerAnimated(viewController: UIViewController, animated: boolean): void {
-		let navigationTransition = <NavigationTransition>viewController[TRANSITION];
+		const navigationTransition = <NavigationTransition>viewController[TRANSITION];
 		if (Trace.isEnabled()) {
 			Trace.write(`UINavigationControllerImpl.pushViewControllerAnimated(${viewController}, ${animated}); transition: ${JSON.stringify(navigationTransition)}`, Trace.categories.NativeLifecycle);
 		}
 
-		let nativeTransition = _getNativeTransition(navigationTransition, true);
+		const nativeTransition = _getNativeTransition(navigationTransition, true);
 		if (!animated || !navigationTransition || !nativeTransition) {
 			super.pushViewControllerAnimated(viewController, animated);
 
@@ -470,14 +471,14 @@ class UINavigationControllerImpl extends UINavigationController {
 
 	@profile
 	public setViewControllersAnimated(viewControllers: NSArray<any>, animated: boolean): void {
-		let viewController = viewControllers.lastObject;
-		let navigationTransition = <NavigationTransition>viewController[TRANSITION];
+		const viewController = viewControllers.lastObject;
+		const navigationTransition = <NavigationTransition>viewController[TRANSITION];
 
 		if (Trace.isEnabled()) {
 			Trace.write(`UINavigationControllerImpl.setViewControllersAnimated(${viewControllers}, ${animated}); transition: ${JSON.stringify(navigationTransition)}`, Trace.categories.NativeLifecycle);
 		}
 
-		let nativeTransition = _getNativeTransition(navigationTransition, true);
+		const nativeTransition = _getNativeTransition(navigationTransition, true);
 		if (!animated || !navigationTransition || !nativeTransition) {
 			super.setViewControllersAnimated(viewControllers, animated);
 
@@ -490,8 +491,8 @@ class UINavigationControllerImpl extends UINavigationController {
 	}
 
 	public popViewControllerAnimated(animated: boolean): UIViewController {
-		let lastViewController = this.viewControllers.lastObject;
-		let navigationTransition = <NavigationTransition>lastViewController[TRANSITION];
+		const lastViewController = this.viewControllers.lastObject;
+		const navigationTransition = <NavigationTransition>lastViewController[TRANSITION];
 		if (Trace.isEnabled()) {
 			Trace.write(`UINavigationControllerImpl.popViewControllerAnimated(${animated}); transition: ${JSON.stringify(navigationTransition)}`, Trace.categories.NativeLifecycle);
 		}
@@ -501,7 +502,7 @@ class UINavigationControllerImpl extends UINavigationController {
 			return super.popViewControllerAnimated(false);
 		}
 
-		let nativeTransition = _getNativeTransition(navigationTransition, false);
+		const nativeTransition = _getNativeTransition(navigationTransition, false);
 		if (!animated || !navigationTransition || !nativeTransition) {
 			return super.popViewControllerAnimated(animated);
 		}
@@ -514,8 +515,8 @@ class UINavigationControllerImpl extends UINavigationController {
 	}
 
 	public popToViewControllerAnimated(viewController: UIViewController, animated: boolean): NSArray<UIViewController> {
-		let lastViewController = this.viewControllers.lastObject;
-		let navigationTransition = <NavigationTransition>lastViewController[TRANSITION];
+		const lastViewController = this.viewControllers.lastObject;
+		const navigationTransition = <NavigationTransition>lastViewController[TRANSITION];
 		if (Trace.isEnabled()) {
 			Trace.write(`UINavigationControllerImpl.popToViewControllerAnimated(${viewController}, ${animated}); transition: ${JSON.stringify(navigationTransition)}`, Trace.categories.NativeLifecycle);
 		}
@@ -525,7 +526,7 @@ class UINavigationControllerImpl extends UINavigationController {
 			return super.popToViewControllerAnimated(viewController, false);
 		}
 
-		let nativeTransition = _getNativeTransition(navigationTransition, false);
+		const nativeTransition = _getNativeTransition(navigationTransition, false);
 		if (!animated || !navigationTransition || !nativeTransition) {
 			return super.popToViewControllerAnimated(viewController, animated);
 		}

packages/core/ui/frame/transition-definitions.android.d.ts

@@ -1,6 +1,6 @@
 // Definitions for Android API lvl 21 transitions
-declare module android {
-	export module transition {
+declare namespace android {
+	export namespace transition {
 		export abstract class Transition extends java.lang.Object {
 			addListener(transition: Transition.TransitionListener): Transition;
 			removeListener(transition: Transition.TransitionListener): Transition;
@@ -26,7 +26,7 @@ declare module android {
 			constructor();
 		}
 
-		export module Transition {
+		export namespace Transition {
 			export interface TransitionListener {
 				onTransitionStart(transition: android.transition.Transition): void;
 				onTransitionEnd(transition: android.transition.Transition): void;
@@ -37,7 +37,7 @@ declare module android {
 		}
 	}
 
-	export module app {
+	export namespace app {
 		export interface Fragment {
 			getEnterTransition(): android.transition.Transition;
 			getExitTransition(): android.transition.Transition;

packages/core/ui/gestures/gestures-common.ts

@@ -26,7 +26,7 @@ export enum SwipeDirection {
 	down = 1 << 3,
 }
 
-export module TouchAction {
+export namespace TouchAction {
 	export const down = 'down';
 	export const up = 'up';
 	export const move = 'move';
@@ -34,7 +34,7 @@ export module TouchAction {
 }
 
 export function toString(type: GestureTypes, separator?: string): string {
-	let types = new Array<string>();
+	const types = new Array<string>();
 
 	if (type & GestureTypes.tap) {
 		types.push('tap');
@@ -74,7 +74,7 @@ export function toString(type: GestureTypes, separator?: string): string {
 // NOTE: toString could return the text of multiple GestureTypes.
 // Souldn't fromString do split on separator and return multiple GestureTypes?
 export function fromString(type: string): GestureTypes {
-	let t = type.trim().toLowerCase();
+	const t = type.trim().toLowerCase();
 
 	if (t === 'tap') {
 		return GestureTypes.tap;
@@ -128,7 +128,7 @@ export abstract class GesturesObserverBase implements GesturesObserverDefinition
 	public disconnect() {
 		// remove gesture observer from map
 		if (this.target) {
-			let list = this.target.getGestureObservers(this.type);
+			const list = this.target.getGestureObservers(this.type);
 			if (list && list.length > 0) {
 				for (let i = 0; i < list.length; i++) {
 					if (list[i].callback === this.callback) {

packages/core/ui/gestures/index.android.ts

@@ -29,7 +29,7 @@ function initializeTapAndDoubleTapGestureListener() {
 		private _target: View;
 		private _type: number;
 
-		private _lastUpTime: number = 0;
+		private _lastUpTime = 0;
 		private _tapTimeoutId: number;
 
 		private static DoubleTapTimeout = android.view.ViewConfiguration.getDoubleTapTimeout();
@@ -187,8 +187,8 @@ function initializeSwipeGestureListener() {
 			let result = false;
 			let args: SwipeGestureEventData;
 			try {
-				let deltaY = currentEvent.getY() - initialEvent.getY();
-				let deltaX = currentEvent.getX() - initialEvent.getX();
+				const deltaY = currentEvent.getY() - initialEvent.getY();
+				const deltaX = currentEvent.getX() - initialEvent.getX();
 
 				if (Math.abs(deltaX) > Math.abs(deltaY)) {
 					if (Math.abs(deltaX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
@@ -479,7 +479,7 @@ class CustomPanGestureDetector {
 
 	private trackStop(currentEvent: android.view.MotionEvent, cacheEvent: boolean) {
 		if (this.isTracking) {
-			let args = _getPanArgs(this.deltaX, this.deltaY, this.target, GestureStateTypes.ended, null, currentEvent);
+			const args = _getPanArgs(this.deltaX, this.deltaY, this.target, GestureStateTypes.ended, null, currentEvent);
 			_executeCallback(this.observer, args);
 
 			this.deltaX = undefined;
@@ -495,21 +495,21 @@ class CustomPanGestureDetector {
 	}
 
 	private trackStart(currentEvent: android.view.MotionEvent) {
-		let inital = this.getEventCoordinates(this.lastEventCache ? this.lastEventCache : currentEvent);
+		const inital = this.getEventCoordinates(this.lastEventCache ? this.lastEventCache : currentEvent);
 		this.initialX = inital.x;
 		this.initialY = inital.y;
 		this.isTracking = true;
 
-		let args = _getPanArgs(0, 0, this.target, GestureStateTypes.began, null, currentEvent);
+		const args = _getPanArgs(0, 0, this.target, GestureStateTypes.began, null, currentEvent);
 		_executeCallback(this.observer, args);
 	}
 
 	private trackChange(currentEvent: android.view.MotionEvent) {
-		let current = this.getEventCoordinates(currentEvent);
+		const current = this.getEventCoordinates(currentEvent);
 		this.deltaX = current.x - this.initialX;
 		this.deltaY = current.y - this.initialY;
 
-		let args = _getPanArgs(this.deltaX, this.deltaY, this.target, GestureStateTypes.changed, null, currentEvent);
+		const args = _getPanArgs(this.deltaX, this.deltaY, this.target, GestureStateTypes.changed, null, currentEvent);
 		_executeCallback(this.observer, args);
 	}
 
@@ -523,7 +523,7 @@ class CustomPanGestureDetector {
 		} else {
 			const offX = event.getRawX() - event.getX();
 			const offY = event.getRawY() - event.getY();
-			let res = { x: 0, y: 0 };
+			const res = { x: 0, y: 0 };
 
 			for (let i = 0; i < count; i++) {
 				res.x += event.getX(i) + offX;
@@ -560,12 +560,12 @@ class CustomRotateGestureDetector {
 	}
 
 	public onTouchEvent(event: android.view.MotionEvent) {
-		let pointerID = event.getPointerId(event.getActionIndex());
-		let wasTracking = this.isTracking;
+		const pointerID = event.getPointerId(event.getActionIndex());
+		const wasTracking = this.isTracking;
 
 		switch (event.getActionMasked()) {
 			case android.view.MotionEvent.ACTION_DOWN:
-			case android.view.MotionEvent.ACTION_POINTER_DOWN:
+			case android.view.MotionEvent.ACTION_POINTER_DOWN:{
 				let assigned = false;
 				if (this.trackedPtrId1 === INVALID_POINTER_ID && pointerID !== this.trackedPtrId2) {
 					this.trackedPtrId1 = pointerID;
@@ -582,7 +582,7 @@ class CustomRotateGestureDetector {
 					this.executeCallback(event, GestureStateTypes.began);
 				}
 				break;
-
+			}
 			case android.view.MotionEvent.ACTION_MOVE:
 				if (this.isTracking) {
 					this.updateAngle(event);
@@ -617,7 +617,7 @@ class CustomRotateGestureDetector {
 	}
 
 	private executeCallback(event: android.view.MotionEvent, state: GestureStateTypes) {
-		let args = <RotationGestureEventData>{
+		const args = <RotationGestureEventData>{
 			type: GestureTypes.rotation,
 			view: this.target,
 			android: event,
@@ -632,7 +632,7 @@ class CustomRotateGestureDetector {
 	}
 
 	private updateAngle(event: android.view.MotionEvent) {
-		let newPointersAngle = this.getPointersAngle(event);
+		const newPointersAngle = this.getPointersAngle(event);
 		let result = ((newPointersAngle - this.initalPointersAngle) * TO_DEGREES) % 360;
 
 		if (result < -180) {
@@ -646,10 +646,10 @@ class CustomRotateGestureDetector {
 	}
 
 	private getPointersAngle(event: android.view.MotionEvent) {
-		let firstX = event.getX(event.findPointerIndex(this.trackedPtrId1));
-		let firstY = event.getY(event.findPointerIndex(this.trackedPtrId1));
-		let secondX = event.getX(event.findPointerIndex(this.trackedPtrId2));
-		let secondY = event.getY(event.findPointerIndex(this.trackedPtrId2));
+		const firstX = event.getX(event.findPointerIndex(this.trackedPtrId1));
+		const firstY = event.getY(event.findPointerIndex(this.trackedPtrId1));
+		const secondX = event.getX(event.findPointerIndex(this.trackedPtrId2));
+		const secondY = event.getY(event.findPointerIndex(this.trackedPtrId2));
 
 		return Math.atan2(secondY - firstY, secondX - firstX);
 	}

packages/core/ui/gestures/index.d.ts

@@ -86,7 +86,7 @@ export enum SwipeDirection {
 /**
  * Defines a touch action
  */
-export module TouchAction {
+export namespace TouchAction {
 	/**
 	 * Down action.
 	 */

packages/core/ui/gestures/index.ios.ts

@@ -37,7 +37,7 @@ class UIGestureRecognizerDelegateImpl extends NSObject implements UIGestureRecog
 		return false;
 	}
 }
-let recognizerDelegateInstance: UIGestureRecognizerDelegateImpl = <UIGestureRecognizerDelegateImpl>UIGestureRecognizerDelegateImpl.new();
+const recognizerDelegateInstance: UIGestureRecognizerDelegateImpl = <UIGestureRecognizerDelegateImpl>UIGestureRecognizerDelegateImpl.new();
 
 @NativeClass
 class UIGestureRecognizerImpl extends NSObject {
@@ -248,9 +248,9 @@ export class GesturesObserver extends GesturesObserverBase {
 
 	private _detach() {
 		if (this.target && this.target.nativeViewProtected) {
-			for (let name in this._recognizers) {
+			for (const name in this._recognizers) {
 				if (this._recognizers.hasOwnProperty(name)) {
-					let item = <RecognizerCache>this._recognizers[name];
+					const item = <RecognizerCache>this._recognizers[name];
 					this.target.nativeViewProtected.removeGestureRecognizer(item.recognizer);
 
 					item.recognizer = null;
@@ -591,7 +591,7 @@ class TouchGestureEventData implements TouchGestureEventData {
 		if (!this._allPointers) {
 			this._allPointers = [];
 
-			let nsArr = this.ios.event.allTouches.allObjects;
+			const nsArr = this.ios.event.allTouches.allObjects;
 			for (let i = 0; i < nsArr.count; i++) {
 				this._allPointers.push(new Pointer(nsArr.objectAtIndex(i), this.view));
 			}

packages/core/ui/image/image-common.ts

@@ -41,7 +41,7 @@ export abstract class ImageBase extends View implements ImageDefinition {
 			this.isLoading = true;
 
 			const imageLoaded = (source: ImageSource) => {
-				let currentValue = this.src;
+				const currentValue = this.src;
 				if (currentValue !== originalValue) {
 					return;
 				}

packages/core/ui/image/index.ios.ts

@@ -8,7 +8,7 @@ export * from './image-common';
 
 export class Image extends ImageBase {
 	nativeViewProtected: UIImageView;
-	private _imageSourceAffectsLayout: boolean = true;
+	private _imageSourceAffectsLayout = true;
 	private _templateImageWasCreated: boolean;
 
 	public createNativeView() {

packages/core/ui/label/index.ios.ts

@@ -55,7 +55,7 @@ export class Label extends TextBase implements LabelDefinition {
 	}
 
 	public onMeasure(widthMeasureSpec: number, heightMeasureSpec: number): void {
-		let nativeView = this.nativeTextViewProtected;
+		const nativeView = this.nativeTextViewProtected;
 		if (nativeView) {
 			const width = layout.getMeasureSpecSize(widthMeasureSpec);
 			const widthMode = layout.getMeasureSpecMode(widthMeasureSpec);