feat(webpack): read nativescript.config.ts main if set before fallback to package.json (#9769)

implements #9658

BREAKING CHANGES:

Possibly breaking if a project has a main field set in the nativescript.config.ts - since after this lands, this value will be used instead of package.json main.

The impact is likely very small, the steps to migrate:

    (Option A) remove main from nativescript.config.ts if set
    (Option B) update main to the correct path in nativescript.config.ts if set incorrectly

packages/core/config/config.interface.ts

@@ -147,7 +147,7 @@ export interface NativeScriptConfig {
 	 */
 	id?: string;
 	/**
-	 * App's main entry file (currently ignored - set it in package.json main field)
+	 * App's main entry file - this setting overrides the value set in package.json
 	 */
 	main?: string;
 	/**

packages/webpack5/__tests__/helpers/platform.spec.ts

@@ -0,0 +1,49 @@
+import { env } from '../../src/';
+import { addPlatform, getEntryPath } from '../../src/helpers/platform';
+
+import { getValue } from '../../src/helpers/config';
+
+describe('getEntryPath', () => {
+	it('uses platform getEntryPath if the platform specifies it', () => {
+		env.platform = 'testPlatform';
+		addPlatform('testPlatform', {
+			getEntryPath() {
+				return 'custom-entry-path';
+			},
+		});
+
+		const res = getEntryPath();
+		expect(res).toEqual('custom-entry-path');
+
+		// cleanup env
+		delete env.platform;
+	});
+
+	it('uses main from nativescript.config.ts if set', () => {
+		env.ios = true;
+
+		// mock getValue
+		const getValueMock = getValue as jest.Mock;
+		const getValueMockImpl = getValueMock.getMockImplementation();
+
+		getValueMock.mockImplementation((key) => {
+			if (key === 'main') {
+				return 'main-from-config';
+			}
+		});
+
+		const res = getEntryPath();
+		expect(res).toEqual('__jest__/main-from-config');
+
+		// reset mock implementation
+		getValueMock.mockImplementation(getValueMockImpl);
+	});
+
+	it('uses main from package.json', () => {
+		env.ios = true;
+
+		const res = getEntryPath();
+		// set in jest.setup.ts mock for package.json...
+		expect(res).toEqual('__jest__/src/app.js');
+	});
+});

packages/webpack5/scripts/jest.setup.ts

@@ -13,10 +13,10 @@ jest.mock('cosmiconfig', () => ({
 	},
 }));
 
+const getValueMock = jest.fn();
+getValueMock.mockImplementation((key, defaultValue) => defaultValue);
 jest.mock('../src/helpers/config.ts', () => ({
-	getValue(key, defaultValue) {
-		return defaultValue;
-	},
+	getValue: getValueMock,
 }));
 
 jest.mock('os', () => {

packages/webpack5/src/helpers/config.ts

@@ -1,5 +1,5 @@
+import { warnOnce } from './log';
 import { env } from '../index';
-import { error, warnOnce } from './log';
 
 function getCLILib() {
 	if (!env.nativescriptLibPath) {
@@ -28,7 +28,9 @@ export function getValue<T = any>(key: string, defaultValue?: any): T {
 		return defaultValue;
 	}
 
-	return (lib.projectConfigService as {
-		getValue(key: string, defaultValue?: any): T;
-	}).getValue(key, defaultValue);
+	return (
+		lib.projectConfigService as {
+			getValue(key: string, defaultValue?: any): T;
+		}
+	).getValue(key, defaultValue);
 }

packages/webpack5/src/helpers/platform.ts

@@ -2,6 +2,7 @@ import { dirname, resolve } from 'path';
 
 import { getPackageJson, getProjectRootPath } from './project';
 import { error, info, warnOnce } from './log';
+import { getValue } from './config';
 import { env } from '../';
 
 import AndroidPlatform from '../platforms/android';
@@ -99,6 +100,13 @@ export function getEntryPath() {
 		return platform.getEntryPath();
 	}
 
+	// try main from nativescript.config.ts
+	const main = getValue('main');
+
+	if (main) {
+		return resolve(getProjectRootPath(), main);
+	}
+
 	// fallback to main field in package.json
 	const packageJson = getPackageJson();