add support for dynamic filenames

Add support for custom filename template for worker scripts.

README.md

@@ -48,9 +48,11 @@ Options can be passed in to `MonacoWebpackPlugin`. They can be used to generate
 
 * `output` (`string`) - custom output path for worker scripts, relative to the main webpack `output.path`.
   * default value: `''`.
+* `filename` (`string`) - custom filename template for worker scripts, respects the same options as [loader-utils' interpolateName](https://github.com/webpack/loader-utils#interpolatename). Useful for adding content-based hashes so that files can be served with long-lived caching headers.
+  * default value: `'[name].worker.js'`.
 * `languages` (`string[]`) - include only a subset of the languages supported.
   * default value: `['apex', 'azcli', 'bat', 'clojure', 'coffee', 'cpp', 'csharp', 'csp', 'css', 'dockerfile', 'fsharp', 'go', 'handlebars', 'html', 'ini', 'java', 'javascript', 'json', 'less', 'lua', 'markdown', 'msdax', 'mysql', 'objective', 'perl', 'pgsql', 'php', 'postiats', 'powerquery', 'powershell', 'pug', 'python', 'r', 'razor', 'redis', 'redshift', 'ruby', 'rust', 'sb', 'scheme', 'scss', 'shell', 'solidity', 'sql', 'st', 'swift', 'typescript', 'vb', 'xml', 'yaml']`.
-  
+
 Some languages share the same web worker. If one of the following languages is included, you must also include the language responsible for instantiating their shared worker:
 
 | Language      | Instantiator  |

index.d.ts

@@ -17,6 +17,12 @@ interface IMonacoEditorWebpackPluginOpts {
      * Use e.g. '!contextmenu' to exclude a certain feature.
      */
     features?: string[];
+
+    /**
+     * Specify a filename template to use for generated files.
+     * Use e.g. '[name].worker.[contenthash].js' to include content-based hashes.
+     */
+    filename?: string;
 }
 
 declare class MonacoEditorWebpackPlugin extends Plugin {

index.js

@@ -1,5 +1,8 @@
 const path = require('path');
 const webpack = require('webpack');
+const loaderUtils = require('loader-utils');
+const fs = require('fs');
+
 const AddWorkerEntryPointPlugin = require('./plugins/AddWorkerEntryPointPlugin');
 const INCLUDE_LOADER_PATH = require.resolve('./loaders/include');
 
@@ -9,18 +12,29 @@ const EDITOR_MODULE = {
   worker: {
     id: 'vs/editor/editor',
     entry: 'vs/editor/editor.worker',
-    output: 'editor.worker.js',
     fallback: undefined
   },
   alias: undefined,
 };
 const LANGUAGES = require('./languages');
 const FEATURES = require('./features');
 
+/**
+ * Return a resolved path for a given Monaco file.
+ */
 function resolveMonacoPath(filePath) {
   return require.resolve(path.join('monaco-editor/esm', filePath));
 }
 
+/**
+ * Return the interpolated final filename for a worker, respecting the file name template.
+ */
+function getWorkerFilename(filename, entry) {
+  return loaderUtils.interpolateName({resourcePath: entry}, filename, {
+    content: fs.readFileSync(resolveMonacoPath(entry))
+  });
+}
+
 const languagesById = fromPairs(
   flatMap(toPairs(LANGUAGES), ([id, language]) =>
     [id].concat(language.alias || []).map((label) => [label, mixin({ label }, language)])
@@ -57,19 +71,20 @@ class MonacoWebpackPlugin {
     this.options = {
       languages: languages.map((id) => languagesById[id]).filter(Boolean),
       features: features.map(id => featuresById[id]).filter(Boolean),
+      filename: options.filename || "[name].worker.js",
       output,
     };
   }
 
   apply(compiler) {
-    const { languages, features, output } = this.options;
+    const { languages, features, filename, output } = this.options;
     const publicPath = getPublicPath(compiler);
     const modules = [EDITOR_MODULE].concat(languages).concat(features);
     const workers = modules.map(
       ({ label, alias, worker }) => worker && (mixin({ label, alias }, worker))
     ).filter(Boolean);
-    const rules = createLoaderRules(languages, features, workers, output, publicPath);
-    const plugins = createPlugins(workers, output);
+    const rules = createLoaderRules(languages, features, workers, filename, output, publicPath);
+    const plugins = createPlugins(workers, filename, output);
     addCompilerRules(compiler, rules);
     addCompilerPlugins(compiler, plugins);
   }
@@ -89,11 +104,11 @@ function getPublicPath(compiler) {
   return compiler.options.output && compiler.options.output.publicPath || '';
 }
 
-function createLoaderRules(languages, features, workers, outputPath, publicPath) {
+function createLoaderRules(languages, features, workers, filename, outputPath, publicPath) {
   if (!languages.length && !features.length) { return []; }
   const languagePaths = flatArr(languages.map(({ entry }) => entry).filter(Boolean));
   const featurePaths = flatArr(features.map(({ entry }) => entry).filter(Boolean));
-  const workerPaths = fromPairs(workers.map(({ label, output }) => [label, path.join(outputPath, output)]));
+  const workerPaths = fromPairs(workers.map(({ label, entry }) => [label, getWorkerFilename(filename, entry)]));
   if (workerPaths['typescript']) {
     // javascript shares the same worker
     workerPaths['javascript'] = workerPaths['typescript'];
@@ -140,14 +155,14 @@ function createLoaderRules(languages, features, workers, outputPath, publicPath)
   ];
 }
 
-function createPlugins(workers, outputPath) {
+function createPlugins(workers, filename, outputPath) {
   return (
     []
-    .concat(uniqBy(workers, ({ id }) => id).map(({ id, entry, output }) =>
+    .concat(uniqBy(workers, ({ id }) => id).map(({ id, entry }) =>
       new AddWorkerEntryPointPlugin({
         id,
         entry: resolveMonacoPath(entry),
-        filename: path.join(outputPath, output),
+        filename: getWorkerFilename(filename, entry),
         plugins: [
           new webpack.optimize.LimitChunkCountPlugin({ maxChunks: 1 }),
         ],

languages.js

@@ -47,7 +47,6 @@ module.exports = {
     worker: {
       id: 'vs/language/css/cssWorker',
       entry: 'vs/language/css/css.worker',
-      output: 'css.worker.js',
       fallback: 'vs/language/css/cssWorker',
     },
     alias: undefined,
@@ -80,7 +79,6 @@ module.exports = {
     worker: {
       id: 'vs/language/html/htmlWorker',
       entry: 'vs/language/html/html.worker',
-      output: 'html.worker.js',
       fallback: 'vs/language/html/htmlWorker',
     },
     alias: undefined,
@@ -105,7 +103,6 @@ module.exports = {
     worker: {
       id: 'vs/language/json/jsonWorker',
       entry: 'vs/language/json/json.worker',
-      output: 'json.worker.js',
       fallback: 'vs/language/json/jsonWorker',
     },
     alias: undefined,
@@ -258,7 +255,6 @@ module.exports = {
     worker: {
       id: 'vs/language/typescript/tsWorker',
       entry: 'vs/language/typescript/ts.worker',
-      output: 'typescript.worker.js',
       fallback: 'vs/language/typescript/tsWorker',
     },
     alias: undefined,