Support webpack 5

.travis.yml

@@ -23,11 +23,23 @@ env:
   - WEBPACK_VERSION=4 MOCHA_VERSION=6
   - WEBPACK_VERSION=4 MOCHA_VERSION=7
   - WEBPACK_VERSION=4 MOCHA_VERSION=8
+  - WEBPACK_VERSION=5 MOCHA_VERSION=7
+  - WEBPACK_VERSION=5 MOCHA_VERSION=8
 
 before_script:
   - "yarn add -D webpack@$WEBPACK_VERSION"
   - "yarn add -D mocha@$MOCHA_VERSION"
 
+  # Need to skip ts check for getAffectedModuleIds in webpack 4
+  - |
+    if [ $WEBPACK_VERSION == 4 ]; then
+      echo -e "// @ts-nocheck\n/*eslint-disable*/\n$(cat src/webpack/util/getAffectedModuleIds.ts)" > src/webpack/util/getAffectedModuleIds.ts;
+    fi
+  - |
+    if [ $WEBPACK_VERSION == 5 ]; then
+      echo -e "// @ts-nocheck\n$(cat src/webpack/util/webpack4GetBuildStats.ts)" > src/webpack/util/webpack4GetBuildStats.ts;
+    fi
+
 script:
   - yarn run cover
 

package.json

@@ -47,7 +47,7 @@
   "license": "MIT",
   "peerDependencies": {
     "mocha": ">=6 <9",
-    "webpack": "^4.0.0"
+    "webpack": "^4.0.0 || ^5.0.0"
   },
   "devDependencies": {
     "@babel/cli": "^7.0.0",
@@ -66,11 +66,11 @@
     "@types/node": "^12.12.17",
     "@types/sinon": "^9.0.0",
     "@types/sinon-chai": "^3.2.4",
-    "@types/webpack": "^4.41.0",
     "@types/yargs": "^15.0.4",
     "@typescript-eslint/eslint-plugin": "^2.11.0",
     "@typescript-eslint/parser": "^2.11.0",
     "anymatch": "3.1.1",
+    "assert": "^2.0.0",
     "babel-eslint": "^9.0.0",
     "babel-loader": "^8.0.0",
     "babel-plugin-istanbul": "4.1.6",
@@ -79,11 +79,11 @@
     "chai": "^4.1.0",
     "coffee-script": "^1.11.1",
     "cross-env": "6.0.3",
-    "css-loader": "3.2.0",
+    "css-loader": "^5.0.1",
     "del": "5.1.0",
     "del-cli": "3.0.0",
     "eslint": "^6.7.2",
-    "eslint-config-airbnb-base": "12.1.0",
+    "eslint-config-airbnb-base": "^14.2.1",
     "eslint-config-prettier": "^6.7.0",
     "eslint-plugin-import": "^2.9.0",
     "fs-extra": "5.0.0",
@@ -99,16 +99,15 @@
     "np": "5.1.0",
     "nyc": "14.1.1",
     "prettier": "^1.19.1",
-    "sass-loader": "6.0.7",
+    "sass-loader": "^10.1.0",
     "sinon": "^9.0.2",
     "sinon-chai": "^3.5.0",
     "strip-ansi": "^5.2.0",
     "tiny-worker": "2.3.0",
     "ts-mocha": "^7.0.0",
     "typescript": "^3.8.3",
-    "webpack": "4.41.0",
-    "worker-loader": "2.0.0",
-    "write-file-webpack-plugin": "^4.2.0"
+    "webpack": "5.0.0",
+    "worker-loader": "^3.0.5"
   },
   "dependencies": {
     "@babel/runtime-corejs2": "^7.0.0",

src/cli/index.ts

@@ -43,8 +43,8 @@ async function cli() {
       }
       return mochaWebpack.run()
     })
-    .then((failures: number) => {
-      exit(cliOptions.mocha.cli.exit, failures)
+    .then((failures: number | void) => {
+      exit(cliOptions.mocha.cli.exit, failures || 0)
     })
     .catch((e: Error) => {
       if (e) console.error(e.stack) // eslint-disable-line

src/runner/TestRunner.ts

@@ -13,6 +13,8 @@ import createWatchCompiler, {
 import registerInMemoryCompiler from '../webpack/compiler/registerInMemoryCompiler'
 import registerReadyCallback from '../webpack/compiler/registerReadyCallback'
 import getBuildStats, { BuildStats } from '../webpack/util/getBuildStats'
+import webpack4GetBuildStats from '../webpack/util/webpack4GetBuildStats'
+import webpack from 'webpack'
 
 import createWebpackConfig from './runnerUtils/createWebpackConfig'
 import {
@@ -73,7 +75,13 @@ export default class TestRunner extends EventEmitter {
   prepareMocha(webpackConfig: WebpackConfig, stats: Stats): Mocha {
     const mocha: Mocha = initMocha(this.options.mocha, this.cwd)
     const outputPath = webpackConfig.output.path
-    const buildStats: BuildStats = getBuildStats(stats, outputPath)
+
+    let buildStats: BuildStats
+    if (webpack.version[0] === '4') {
+      buildStats = webpack4GetBuildStats(stats, outputPath)
+    } else {
+      buildStats = getBuildStats(stats, outputPath)
+    }
 
     // @ts-ignore
     global.__webpackManifest__ = buildStats.affectedModules // eslint-disable-line
@@ -106,7 +114,7 @@ export default class TestRunner extends EventEmitter {
       failures = await new Promise((resolve, reject) => {
         registerReadyCallback(
           compiler,
-          (err: (Error | string) | null, webpackStats: Stats | null) => {
+          (err: Error, webpackStats: Stats) => {
             this.emit(WEBPACK_READY_EVENT, err, webpackStats)
             if (err || !webpackStats) {
               reject()
@@ -216,7 +224,7 @@ export default class TestRunner extends EventEmitter {
     // register webpack ready callback
     registerReadyCallback(
       compiler,
-      (err: (Error | string) | null, webpackStats: Stats | null) => {
+      (err: Error, webpackStats: Stats) => {
         this.emit(WEBPACK_READY_EVENT, err, webpackStats)
         if (err) {
           // wait for fixed tests

src/runner/runnerUtils/createWebpackConfig/index.ts

@@ -5,7 +5,7 @@ import {
   has as _has,
   merge as _merge
 } from 'lodash'
-import { Configuration, Plugin, RuleSetRule } from 'webpack'
+import { Configuration, WebpackPluginInstance, RuleSetRule } from 'webpack'
 import { glob } from '../../../util/glob'
 import { EntryConfig } from '../../../webpack/loader/entryLoader'
 import { buildProgressPlugin } from '../../../webpack/plugin/buildProgressPlugin'
@@ -48,7 +48,7 @@ const getPublicPath = (
 const buildPluginsArray = (
   webpackConfig: Configuration,
   interactive: boolean
-): Plugin[] => {
+): WebpackPluginInstance[] => {
   const plugins = webpackConfig.plugins || []
 
   if (interactive) {

src/runner/runnerUtils/createWebpackConfig/types.ts

@@ -1,4 +1,4 @@
-import { Configuration, Plugin, RuleSetRule } from 'webpack'
+import { Configuration, WebpackPluginInstance, RuleSetRule } from 'webpack'
 import { EntryConfig } from '../../../webpack/loader/entryLoader'
 
 export interface CreateWebpackConfigOptions {
@@ -19,7 +19,7 @@ export interface BuildLoaderRulesOptions extends CreateWebpackConfigOptions {
 export interface BuildWebpackConfigOptions extends BuildLoaderRulesOptions {
   loaderRules: RuleSetRule[]
   outputPath: string
-  plugins: Plugin[]
+  plugins: WebpackPluginInstance[]
   publicPath: string
 }
 

src/webpack/compiler/registerInMemoryCompiler.ts

@@ -1,3 +1,4 @@
+import fs from 'fs'
 import path from 'path'
 import sourceMapSupport from 'source-map-support'
 import MemoryFileSystem from 'memory-fs'
@@ -13,7 +14,10 @@ export default function registerInMemoryCompiler(
 ): VoidFunction {
   // register memory fs to webpack
   const memoryFs = new MemoryFileSystem()
-  compiler.outputFileSystem = memoryFs // eslint-disable-line no-param-reassign
+  // the flag is used for integration tests that need to read compiled files
+  if (!process.env.MOCHAPACK_WRITE_TO_DISK) {
+    compiler.outputFileSystem = memoryFs // eslint-disable-line no-param-reassign
+  }
 
   // build asset map to allow fast checks for file existence
   const assetMap = new Map()

src/webpack/compiler/registerReadyCallback.ts

@@ -3,14 +3,14 @@ import { MOCHAPACK_NAME } from '../../util/constants'
 
 export default function registerReadyCallback(
   compiler: Compiler,
-  cb: (err: (Error | string) | null, stats: Stats | null) => void
-) {
-  compiler.hooks.failed.tap(MOCHAPACK_NAME, cb)
+  cb: (err: Error, stats: Stats) => void
+  ) {
+  compiler.hooks.failed.tap(MOCHAPACK_NAME, (error: Error) => cb(error, null))
   compiler.hooks.done.tap(MOCHAPACK_NAME, (stats: Stats) => {
     if (stats.hasErrors()) {
       const jsonStats = stats.toJson()
       const [err] = jsonStats.errors
-      cb(err, stats)
+      cb(err as Error, stats)
     } else {
       cb(null, stats)
     }

src/webpack/loader/entryLoader.ts

@@ -31,14 +31,15 @@ export const entryLoader = function entryLoader() {
   // Remove all dependencies of the loader result
   this.clearDependencies()
 
-  const dependencies: Array<string> = config
-    .getFiles()
-    .map(file => loaderUtils.stringifyRequest(this, file))
+
+  const entries = config.getFiles()
 
   // add all entries as dependencies
-  dependencies.forEach(this.addDependency.bind(this))
+  // note this.addDependency requires an absolute path
+  entries.forEach(e => this.addDependency(e))
 
   // build source code
+  const dependencies = entries.map(file => loaderUtils.stringifyRequest(this, file))
   const sourceCode: string = createEntry(dependencies)
 
   this.callback(null, sourceCode, null)

src/webpack/util/createEntry.ts

@@ -8,7 +8,6 @@ export default function createEntry(filePaths: Array<string>): string {
     'var ids = [',
     filePaths.map(path => `require.resolve(${path})`).join(','),
     '];',
-    '',
     'ids.filter(inManifest).forEach(run)'
   ].join('\n')
 }

src/webpack/util/createStatsFormatter.ts

@@ -2,8 +2,8 @@ import { EOL } from 'os'
 import chalk from 'chalk'
 import { Stats } from 'webpack'
 import RequestShortener from 'webpack/lib/RequestShortener'
+import WebpackError from 'webpack/lib/WebpackError'
 import { formatErrorMessage, stripLoaderFromPath } from './formatUtil'
-import { WebpackError } from '../types'
 
 const createGetFile = (requestShortener: RequestShortener) => (
   e: WebpackError