feat: add support for webpack@5 and html-webpack-plugin@5

.github/workflows/node.js.yml

@@ -15,8 +15,24 @@ jobs:
       fail-fast: false
       matrix:
         node-version: [6.x, 8.x, 10.x, 12.x, 14.x, 15.x]
-        html-plugin-version: [3, 4]
-        webpack-version: [4]
+        html-plugin-version: [3, 4, 5]
+        webpack-version: [4, 5]
+        exclude:
+          # plugin@5 only supports webpack@5
+          - html-plugin-version: 5
+            webpack-version: 4
+          # plugin@3 only supports webpack@4
+          - html-plugin-version: 3
+            webpack-version: 5
+          # webpack@5 and plugin@5 does not support node 6 or 8
+          - node-version: 6.x
+            webpack-version: 5
+          - node-version: 6.x
+            html-plugin-version: 5
+          - node-version: 8.x
+            webpack-version: 5
+          - node-version: 8.x
+            html-plugin-version: 5
         include:
           - node-version: 10.x
             install-puppeteer: true

package.json

@@ -54,7 +54,7 @@
     "eslint-config-simenb-base": "^15.0.1",
     "eslint_d": "^7.1.0",
     "express": "^4.17.1",
-    "html-webpack-plugin": "^4.0.0-0",
+    "html-webpack-plugin": "^4.0.0",
     "husky": "^1.0.1",
     "jest": "^24.0.0",
     "jest-watch-typeahead": "^0.2.0",
@@ -67,8 +67,8 @@
     "webpack-cli": "^3.1.0"
   },
   "peerDependencies": {
-    "html-webpack-plugin": "^3.0.4 || ^4.0.0-0",
-    "webpack": "^4.0.0"
+    "html-webpack-plugin": "^3.0.4 || ^4.0.0-0 || ^5.0.0",
+    "webpack": "^4.0.0 || ^5.0.0"
   },
   "engines": {
     "node": ">=6"

src/index.js

@@ -3,13 +3,41 @@ import pEachSeries from 'p-each-series';
 import micromatch from 'micromatch';
 import crypto from 'crypto';
 import globby from 'globby';
+import path from 'path';
+import webpack from 'webpack';
 import {
   ensureTrailingSlash,
+  fsReadFileAsync,
   handleUrl,
   resolveOutput,
   resolvePublicPath,
 } from './utils';
 
+/* istanbul ignore next: webpack 5 not in unit test mocks */
+/**
+ * Pushes the content of the given filename to the compilation assets
+ * @param {string} filename
+ * @param {WebpackCompilation} compilation
+ * @returns {Promise<string>} file basename
+ */
+function addFileToAssetsWebpack5(filename, compilation) {
+  const resolvedFilename = path.resolve(compilation.compiler.context, filename);
+
+  return fsReadFileAsync(resolvedFilename)
+    .then(source => new webpack.sources.RawSource(source, true))
+    .catch(() =>
+      Promise.reject(
+        new Error(`HtmlWebpackPlugin: could not load file ${resolvedFilename}`),
+      ),
+    )
+    .then(rawSource => {
+      const basename = path.basename(resolvedFilename);
+      compilation.fileDependencies.add(resolvedFilename);
+      compilation.emitAsset(basename, rawSource);
+      return basename;
+    });
+}
+
 export default class AddAssetHtmlPlugin {
   constructor(assets = []) {
     this.assets = Array.isArray(assets) ? assets.slice().reverse() : [assets];
@@ -22,7 +50,7 @@ export default class AddAssetHtmlPlugin {
       let beforeGenerationHook;
       let alterAssetTagsHook;
 
-      if (HtmlWebpackPlugin.version === 4) {
+      if (HtmlWebpackPlugin.version >= 4) {
         const hooks = HtmlWebpackPlugin.getHooks(compilation);
 
         beforeGenerationHook = hooks.beforeAssetTagGeneration;
@@ -105,10 +133,11 @@ export default class AddAssetHtmlPlugin {
       }
     }
 
-    const addedFilename = await htmlPluginData.plugin.addFileToAssets(
-      filepath,
-      compilation,
-    );
+    const addFileToAssets =
+      htmlPluginData.plugin.addFileToAssets ||
+      /* istanbul ignore next: webpack 5 not in unit test mocks */ addFileToAssetsWebpack5;
+
+    const addedFilename = await addFileToAssets(filepath, compilation);
 
     let suffix = '';
     if (hash) {
@@ -133,7 +162,7 @@ export default class AddAssetHtmlPlugin {
       const relatedFiles = await globby(`${filepath}.*`);
       await Promise.all(
         relatedFiles.sort().map(async relatedFile => {
-          const addedMapFilename = await htmlPluginData.plugin.addFileToAssets(
+          const addedMapFilename = await addFileToAssets(
             relatedFile,
             compilation,
           );

src/utils.js

@@ -1,5 +1,6 @@
 import path from 'path';
 import globby from 'globby';
+import fs from 'fs';
 
 export function ensureTrailingSlash(string) {
   if (string.length && string.substr(-1, 1) !== '/') {
@@ -30,6 +31,19 @@ export function resolveOutput(compilation, addedFilename, outputPath) {
   }
 }
 
+/* istanbul ignore next: webpack 5 not in unit test mocks */
+export function fsReadFileAsync(filePath) {
+  return new Promise((resolve, reject) => {
+    fs.readFile(filePath, (err, res) => {
+      if (err) {
+        reject(err);
+      } else {
+        resolve(res);
+      }
+    });
+  });
+}
+
 /**
  * handle globby filepath and return an array with all matched assets.
  *

yarn.lock

@@ -3869,7 +3869,7 @@ html-minifier-terser@^5.0.1:
     relateurl "^0.2.7"
     terser "^4.6.3"
 
-html-webpack-plugin@^4.0.0-0:
+html-webpack-plugin@^4.0.0:
   version "4.5.2"
   resolved "https://registry.yarnpkg.com/html-webpack-plugin/-/html-webpack-plugin-4.5.2.tgz#76fc83fa1a0f12dd5f7da0404a54e2699666bc12"
   integrity sha512-q5oYdzjKUIPQVjOosjgvCHQOv9Ett9CYYHlgvJeXG0qQvdSojnBq4vAdQBwn1+yGveAwHCoe/rMR86ozX3+c2A==