add support for plugin-specific public path

Override the public path from which files generated by this plugin will be served. This wins out over Webpack's dynamic runtime path and can be useful to avoid attempting to load workers cross-origin when using a CDN for other static resources.

README.md

@@ -48,6 +48,8 @@ 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: `''`.
+* `publicPath` (`string`) - custom public path for worker scripts, overrides the public path from which files generated by this plugin will be served. This wins out over Webpack's dynamic runtime path and can be useful to avoid attempting to load workers cross-origin when using a CDN for other static resources. Use e.g. '/' if you want to load your resources from the current origin..
+  * default value: `''`.
 * `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']`.
 

index.d.ts

@@ -17,6 +17,14 @@ interface IMonacoEditorWebpackPluginOpts {
      * Use e.g. '!contextmenu' to exclude a certain feature.
      */
     features?: string[];
+
+    /**
+     * Override the public path from which files generated by this plugin will be served.
+     * This wins out over Webpack's dynamic runtime path and can be useful to avoid attempting to load workers cross-
+     * origin when using a CDN for other static resources.
+     * Use e.g. '/' if you want to load your resources from the current origin.
+     */
+    publicPath?: string;
 }
 
 declare class MonacoEditorWebpackPlugin extends Plugin {

index.js

@@ -53,22 +53,22 @@ class MonacoWebpackPlugin {
   constructor(options = {}) {
     const languages = options.languages || Object.keys(languagesById);
     const features = getFeaturesIds(options.features || [], featuresById);
-    const output = options.output || '';
     this.options = {
       languages: languages.map((id) => languagesById[id]).filter(Boolean),
       features: features.map(id => featuresById[id]).filter(Boolean),
-      output,
+      output: options.output || '',
+      publicPath: options.publicPath || ''
     };
   }
 
   apply(compiler) {
-    const { languages, features, output } = this.options;
+    const { languages, features, output, publicPath } = this.options;
-    const publicPath = getPublicPath(compiler);
+    const compilationPublicPath = getCompilationPublicPath(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 rules = createLoaderRules(languages, features, workers, output, publicPath, compilationPublicPath);
     const plugins = createPlugins(workers, output);
     addCompilerRules(compiler, rules);
     addCompilerPlugins(compiler, plugins);
@@ -85,11 +85,11 @@ function addCompilerPlugins(compiler, plugins) {
   plugins.forEach((plugin) => plugin.apply(compiler));
 }
 
-function getPublicPath(compiler) {
+function getCompilationPublicPath(compiler) {
   return compiler.options.output && compiler.options.output.publicPath || '';
 }
 
-function createLoaderRules(languages, features, workers, outputPath, publicPath) {
+function createLoaderRules(languages, features, workers, outputPath, pluginPublicPath, compilationPublicPath) {
   if (!languages.length && !features.length) { return []; }
   const languagePaths = flatArr(languages.map(({ entry }) => entry).filter(Boolean));
   const featurePaths = flatArr(features.map(({ entry }) => entry).filter(Boolean));
@@ -110,6 +110,16 @@ function createLoaderRules(languages, features, workers, outputPath, publicPath)
     workerPaths['razor'] = workerPaths['html'];
   }
 
+  // Determine the public path from which to load worker JS files. In order of precedence:
+  // 1. Plugin-specific public path.
+  // 2. Dynamic runtime public path.
+  // 3. Compilation public path.
+  const pathPrefix = Boolean(pluginPublicPath)
+    ? JSON.stringify(pluginPublicPath)
+    : `typeof window.__webpack_public_path__ === 'string' ` +
+      `? window.__webpack_public_path__ ` +
+      `: ${JSON.stringify(compilationPublicPath)}`
+
   const globals = {
     'MonacoEnvironment': `(function (paths) {
       function stripTrailingSlash(str) {
@@ -117,7 +127,7 @@ function createLoaderRules(languages, features, workers, outputPath, publicPath)
       }
       return {
         getWorkerUrl: function (moduleId, label) {
-          var pathPrefix = (typeof window.__webpack_public_path__ === 'string' ? window.__webpack_public_path__ : ${JSON.stringify(publicPath)});
+          var pathPrefix = ${pathPrefix};
           return (pathPrefix ? stripTrailingSlash(pathPrefix) + '/' : '') + paths[label];
         }
       };