Getting closer.

Author: jeffposnick

package-lock.json

@@ -42,6 +42,7 @@
     "eslint-config-google": "^0.9.1",
     "jasmine": "^3.1.0",
     "jsdom": "^11.6.2",
+    "memory-fs": "^0.4.1",
     "rimraf": "^2.6.2"
   },
   "peerDependencies": {

package.json

@@ -15,6 +15,8 @@
  * limitations under the License.
  */
 
+const assert = require('assert');
+
 const createHTMLElementString = require('./lib/create-html-element-string');
 const defaultOptions = require('./lib/default-options');
 const determineAsValue = require('./lib/determine-as-value');
@@ -27,26 +29,44 @@ class PreloadPlugin {
     this.options = Object.assign({}, defaultOptions, options);
   }
 
-  addLinks(compilation, htmlPluginData) {
-    const options = this.options;
-
-    const extractedChunks = extractChunks(compilation, options.include);
+  addLinks(webpackVersion, compilation, htmlPluginData) {
+    assert(webpackVersion in doesChunkBelongToHTML,
+      `An invalid webpackVersion was supplied. Supported values: ${Object.keys(doesChunkBelongToHTML)}.`);
 
-    const publicPath = compilation.outputOptions.publicPath || '';
+    const options = this.options;
 
-    // Only handle chunks imported by this HtmlWebpackPlugin.
-    const htmlChunks = extractedChunks.filter(
-      (chunk) => doesChunkBelongToHTML(chunk, Object.values(htmlPluginData.assets.chunks), {}));
+    // Bail out early if we're configured to exclude this HTML file.
+    if (options.excludeHtmlNames.includes(htmlPluginData.plugin.options.filename)) {
+      return htmlPluginData;
+    }
 
+    const extractedChunks = extractChunks({
+      compilation,
+      optionsInclude: options.include,
+    });
+
+    const htmlChunks = options.include === 'allAssets' ?
+      // Handle all chunks.
+      extractedChunks :
+      // Only handle chunks imported by this HtmlWebpackPlugin.
+      extractedChunks.filter((chunk) => doesChunkBelongToHTML[webpackVersion]({
+        chunk,
+        compilation,
+        htmlAssetsChunks: Object.values(htmlPluginData.assets.chunks),
+      }));
+
+    // Flatten the list of files.
     const allFiles = htmlChunks.reduce((accumulated, chunk) => {
       return accumulated.concat(chunk.files);
     }, []);
     const uniqueFiles = new Set(allFiles);
     const filteredFiles = [...uniqueFiles].filter(
       (file) => this.options.fileBlacklist.every(regex => !regex.test(file)));
+    // Sort to ensure the output is predictable.
     const sortedFilteredFiles = filteredFiles.sort();
 
     const links = [];
+    const publicPath = compilation.outputOptions.publicPath || '';
     for (const file of sortedFilteredFiles) {
       const href = `${publicPath}${file}`;
 
@@ -86,7 +106,7 @@ class PreloadPlugin {
             this.constructor.name,
             (htmlPluginData, callback) => {
               try {
-                callback(null, this.addLinks(compilation, htmlPluginData));
+                callback(null, this.addLinks('v4', compilation, htmlPluginData));
               } catch (error) {
                 callback(error);
               }
@@ -98,7 +118,7 @@ class PreloadPlugin {
       compiler.plugin('compilation', (compilation) => {
         compilation.plugin('html-webpack-plugin-before-html-processing', (htmlPluginData, callback) => {
           try {
-            callback(null, this.addLinks(compilation, htmlPluginData));
+            callback(null, this.addLinks('v3', compilation, htmlPluginData));
           } catch (error) {
             callback(error);
           }

src/index.js

@@ -18,6 +18,7 @@
 const defaultOptions = {
   rel: 'preload',
   include: 'asyncChunks',
+  excludeHtmlNames: [],
   fileBlacklist: [/\.map/]
 };
 

src/lib/default-options.js

@@ -15,31 +15,41 @@
  * limitations under the License.
  */
 
-function doesChunkBelongToHTML(chunk, roots, visitedChunks) {
+function v3({chunk, htmlAssetsChunks, visitedChunks = {}}) {
   // Prevent circular recursion.
   // See https://github.com/GoogleChromeLabs/preload-webpack-plugin/issues/49
   if (visitedChunks[chunk.renderedHash]) {
     return false;
   }
   visitedChunks[chunk.renderedHash] = true;
 
-  for (const root of roots) {
-    if (root.hash === chunk.renderedHash) {
+  for (const htmlAssetChunk of htmlAssetsChunks) {
+    if (htmlAssetChunk.hash === chunk.renderedHash) {
       return true;
     }
   }
 
-  const parents = ('_groups' in chunk) ?
-    chunk.getParents() :
-    chunk.parents;
-
-  for (const parent of parents) {
-    if (doesChunkBelongToHTML(parent, roots, visitedChunks)) {
+  for (const parent of chunk.parents) {
+    if (v3({chunk: parent, htmlAssetsChunks, visitedChunks})) {
       return true;
     }
   }
 
   return false;
 }
 
-module.exports = doesChunkBelongToHTML;
+function v4({chunk, htmlAssetsChunks, compilation}) {
+  // Get all the hashes of the HTML assets.
+  const rootHashes = Object.values(htmlAssetsChunks).map(({hash}) => hash);
+  // Get a list of chunk groups that contain one of those hashes.
+  const rootChunkGroups = compilation.chunkGroups.filter((chunkGroup) => {
+    return chunkGroup.chunks.filter((chunk) => rootHashes.includes(chunk.renderedHash));
+  });
+  // Get an id for each of those chunk groups.
+  const rootChunkGroupsIds = new Set(rootChunkGroups.map(({id}) => id));
+  // Return true iff the chunk we're passed belongs to a group whose id is in
+  // the list of root chunk groups.
+  return Array.from(chunk.groupsIterable).some(({id}) => rootChunkGroupsIds.has(id));
+}
+
+module.exports = {v3, v4};

src/lib/does-chunk-belong-to-html.js

@@ -15,18 +15,30 @@
  * limitations under the License.
  */
 
-function extractChunks(compilation, optionsInclude) {
+function extractChunks({compilation, optionsInclude}) {
   try {
     // 'asyncChunks' are chunks intended for lazy/async loading usually generated as
     // part of code-splitting with import() or require.ensure(). By default, asyncChunks
     // get wired up using link rel=preload when using this plugin. This behaviour can be
     // configured to preload all types of chunks or just prefetch chunks as needed.
     if (optionsInclude === undefined || optionsInclude === 'asyncChunks') {
-      return compilation.chunks.filter(chunk => !chunk.isInitial());
+      return compilation.chunks.filter(chunk => {
+        if ('canBeInitial' in chunk) {
+          return !chunk.canBeInitial();
+        } else {
+          return !chunk.isInitial();
+        }
+      });
     }
 
     if (optionsInclude === 'initial') {
-      return compilation.chunks.filter(chunk => chunk.isInitial());
+      return compilation.chunks.filter(chunk => {
+        if ('canBeInitial' in chunk) {
+          return chunk.canBeInitial();
+        } else {
+          return chunk.isInitial();
+        }
+      });
     }
 
     if (optionsInclude === 'all') {
@@ -36,9 +48,7 @@ function extractChunks(compilation, optionsInclude) {
 
     if (Array.isArray(optionsInclude)) {
       // Keep only user specified chunks.
-      return compilation.chunks.filter((chunk) => {
-        return chunk.name && optionsInclude.includes(chunk.name);
-      });
+      return compilation.chunks.filter((chunk) => chunk.name && optionsInclude.includes(chunk.name));
     }
   } catch (error) {
     return compilation.chunks;