feat: webpackChain options

Implement { last: true }

packages/webpack5/__tests__/index.spec.ts

@@ -1,8 +1,11 @@
-// @ts-ignore
-import Config from 'webpack-chain';
-import * as webpack from '../src';
-
 describe('@nativescript/webpack', () => {
+	let webpack: typeof import('../src');
+
+	beforeEach(() => {
+		jest.resetModules();
+		webpack = require('../src');
+	});
+
 	it('exports the public api', () => {
 		expect(webpack.init).toBeInstanceOf(Function);
 		expect(webpack.useConfig).toBeInstanceOf(Function);
@@ -27,7 +30,29 @@ describe('@nativescript/webpack', () => {
 
 		expect(chainFn).toHaveBeenCalledTimes(1);
 		expect(chainFn).toHaveBeenCalledWith(config, {});
-		expect(config).toBeInstanceOf(Config);
+	});
+
+	it('applies chain configs in the right order', () => {
+		webpack.useConfig(false);
+		let lastCalled = false;
+
+		// this is registered before chainFnNormal
+		// however, should be called after chainFnNormal
+		const chainFnLast = jest.fn((config) => {
+			lastCalled = true;
+			expect(config.normal).toBe(true);
+		});
+		webpack.chainWebpack(chainFnLast, { last: true });
+
+		const chainFnNormal = jest.fn((config) => {
+			config.normal = true;
+
+			// chainFnLast should not have been called yet
+			expect(lastCalled).toBe(false);
+		});
+		webpack.chainWebpack(chainFnNormal);
+
+		webpack.resolveChainableConfig();
 	});
 
 	it('applies merge configs', () => {

packages/webpack5/src/index.ts

@@ -30,7 +30,11 @@ export interface IWebpackEnv {
 	// todo: add others
 }
 
-let webpackChains: any[] = [];
+let webpackChains = {
+	base: [],
+	normal: [],
+	last: [],
+};
 let webpackMerges: any[] = [];
 let explicitUseConfig = false;
 let hasInitialized = false;
@@ -54,7 +58,7 @@ export function init(_env: IWebpackEnv) {
 export function useConfig(config: keyof typeof defaultConfigs | false) {
 	explicitUseConfig = true;
 	if (config) {
-		webpackChains.unshift(configs[config]);
+		webpackChains.base.push(configs[config]);
 	}
 }
 
@@ -62,8 +66,8 @@ export function chainWebpack(
 	chainFn: (config: Config, env: IWebpackEnv) => any,
 	options?: { last?: boolean }
 ) {
-	// todo: handle options.last by storing them in a separate array?
-	webpackChains.push(chainFn);
+	const type = options?.last ? 'last' : 'normal';
+	webpackChains[type].push(chainFn);
 }
 
 export function mergeWebpack(
@@ -75,7 +79,7 @@ export function mergeWebpack(
 	webpackMerges.push(mergeFn);
 }
 
-export function resolveChainableConfig() {
+export function resolveChainableConfig(): Config {
 	const config = new Config();
 
 	if (!explicitUseConfig) {
@@ -86,10 +90,19 @@ export function resolveChainableConfig() {
 	// todo: allow opt-out
 	applyExternalConfigs();
 
-	// this applies all chain configs
-	webpackChains.forEach((chainFn) => {
+	const applyChains = (chains) => {
+		// this applies the chain configs
+		chains.forEach((chainFn) => {
 			return chainFn(config, env);
 		});
+	};
+
+	// first we apply base configs
+	applyChains(webpackChains.base);
+	// then regular configs
+	applyChains(webpackChains.normal);
+	// finally configs that opted to be called last
+	applyChains(webpackChains.last);
 
 	if (env.verbose) {
 		info('Resolved chainable config (before merges):');
@@ -99,7 +112,9 @@ export function resolveChainableConfig() {
 	return config;
 }
 
-export function resolveConfig(chainableConfig = resolveChainableConfig()) {
+export function resolveConfig(
+	chainableConfig = resolveChainableConfig()
+): webpack.Configuration {
 	if (!hasInitialized) {
 		throw error('resolveConfig() must be called after init()');
 	}