feat: add option to merge files (options.merge)

README.md

@@ -75,6 +75,7 @@ new ExtractTextPlugin(options: filename | object)
 |**`allChunks`**|`{Boolean}`|Extract from all additional chunks too (by default it extracts only from the initial chunk(s))<br />When using `CommonsChunkPlugin` and there are extracted chunks (from `ExtractTextPlugin.extract`) in the commons chunk, `allChunks` **must** be set to `true`|
 |**`disable`**|`{Boolean}`|Disables the plugin|
 |**`ignoreOrder`**|`{Boolean}`|Disables order check (useful for CSS Modules!), `false` by default|
+|**`merge`**|`{Array}`|List of files to create merging other files. Each element should be like `{ test, filename, preventOriginalOutput}`|
 
 * `[name]` name of the chunk
 * `[id]` number of the chunk
@@ -84,7 +85,22 @@ new ExtractTextPlugin(options: filename | object)
   * other `digestType`s, e.g. `hex`, `base26`, `base32`, `base36`, `base49`, `base52`, `base58`, `base62`, `base64`
   * and `length`, the length of the hash in chars
 
-> :warning: `ExtractTextPlugin` generates a file **per entry**, so you must use `[name]`, `[id]` or `[contenthash]` when using multiple entries.
+> :warning: `ExtractTextPlugin` generates a file **per entry**, so you must use `[name]`, `[id]` or `[contenthash]` when using multiple entries, or set the `merge` option.
+
+```js
+// Generate one styles.css from all the *.styles.css and one themes.css from all the *.themes.css files
+new ExtractTextPlugin({
+  merge: [{
+    filename: 'styles.css', // name of the merged output file (required)
+    test: /\.styles\.css$/, // files to include (*.styles.css) (required)
+    originals: false,       // when false (by default), original files won't be generated
+  }, {
+    filename: 'themes.css',
+    test: /\.themes\.css$/,
+    originals: true,
+  }]
+})
+```
 
 #### `#extract`
 

schema/loader.json

@@ -25,6 +25,9 @@
 		},
 		"publicPath": {
 			"type": "string"
-		}
+		},
+		"merge": {
+      "type": "array"
+    }
 	}
 }

schema/plugin.json

@@ -35,6 +35,10 @@
     "publicPath": {
       "description": "",
       "type": "string"
+    },
+    "merge": {
+      "description": "List of objects as { filename, test, preventOriginalOutput }",
+      "type": "array"
     }
   }
 }

src/index.js

@@ -30,7 +30,10 @@ class ExtractTextPlugin {
     }
     this.filename = options.filename;
     this.id = options.id != null ? options.id : ++nextId;
-    this.options = {};
+    this.options = {
+      merge: [],
+    };
+    this.filesToMerge = {};
     mergeOptions(this.options, options);
     delete this.options.filename;
     delete this.options.id;
@@ -55,6 +58,23 @@ class ExtractTextPlugin {
     return ExtractTextPlugin.loader(mergeOptions({ id: this.id }, options));
   }
 
+  mergeChunks(chunks, filename) {
+    const result = new Chunk();
+    // result.index = i;
+    // result.originalChunk = chunk;
+    result.name = filename;
+    result.entrypoints = [];
+
+    chunks.forEach((chunk) => {
+      // result.entrypoints = result.entrypoints.concat(chunk.entrypoints);
+      chunk.forEachModule((module) => {
+        result.addModule(module);
+        module.addChunk(result);
+      });
+    });
+    return result;
+  }
+
   mergeNonInitialChunks(chunk, intoChunk, checkedChunks) {
     if (!intoChunk) {
       checkedChunks = [];
@@ -215,10 +235,43 @@ class ExtractTextPlugin {
 
             const file = (isFunction(filename)) ? filename(getPath) : getPath(filename);
 
-            compilation.assets[file] = source;
-            chunk.files.push(file);
+            let outputOriginals = this.options.merge.length === 0;
+            let matched = false;
+            this.options.merge.forEach((mergeConfig) => {
+              if (mergeConfig.test.test(file)) {
+                matched = true;
+                if (!this.filesToMerge[mergeConfig.filename]) {
+                  this.filesToMerge[mergeConfig.filename] = [];
+                }
+                this.filesToMerge[mergeConfig.filename].push(extractedChunk);
+                outputOriginals = outputOriginals || mergeConfig.originals;
+              }
+            });
+
+            if (!matched || outputOriginals) {
+              compilation.assets[file] = source;
+              chunk.files.push(file);
+            }
           }
         }, this);
+
+        Object.keys(this.filesToMerge).forEach((f) => {
+          const chunks = this.filesToMerge[f];
+          const mergedChunk = this.mergeChunks(chunks);
+          const source = this.renderExtractedChunk(mergedChunk);
+
+          const getPath = format => compilation.getPath(format, {
+            mergedChunk,
+          }).replace(/\[(?:(\w+):)?contenthash(?::([a-z]+\d*))?(?::(\d+))?\]/ig, function () { // eslint-disable-line func-names
+            return loaderUtils.getHashDigest(source.source(), arguments[1], arguments[2], parseInt(arguments[3], 10));
+          });
+
+          const file = (isFunction(f)) ? filename(getPath) : getPath(f);
+
+          compilation.assets[file] = source;
+          mergedChunk.files.push(file);
+        });
+
         callback();
       });
     });

test/__snapshots__/webpack-integration.test.js.snap

@@ -71,6 +71,28 @@ exports[`Webpack Integration Tests merging-multiple-entries-shared 2`] = `
 "
 `;
 
+exports[`Webpack Integration Tests merging-multiple-outputs 1`] = `
+"c
+d
+"
+`;
+
+exports[`Webpack Integration Tests merging-multiple-outputs 2`] = `
+"a
+"
+`;
+
+exports[`Webpack Integration Tests merging-multiple-outputs 3`] = `
+"b
+"
+`;
+
+exports[`Webpack Integration Tests merging-multiple-outputs 4`] = `
+"a
+b
+"
+`;
+
 exports[`Webpack Integration Tests multiple-entries 1`] = `
 "a
 b

test/cases/merging-multiple-outputs/a.txt

@@ -0,0 +1 @@
+a

test/cases/merging-multiple-outputs/b.txt

@@ -0,0 +1 @@
+b

test/cases/merging-multiple-outputs/bar-1.js

@@ -0,0 +1,3 @@
+require.ensure([], () => {
+  require('./c.txt');
+});

test/cases/merging-multiple-outputs/bar-2.js

@@ -0,0 +1,3 @@
+require.ensure([], () => {
+  require('./d.txt');
+});

test/cases/merging-multiple-outputs/c.txt

@@ -0,0 +1 @@
+c

test/cases/merging-multiple-outputs/d.txt

@@ -0,0 +1 @@
+d

test/cases/merging-multiple-outputs/expected/bar.txt

@@ -0,0 +1,2 @@
+c
+d

test/cases/merging-multiple-outputs/expected/foo-1.txt

@@ -0,0 +1 @@
+a

test/cases/merging-multiple-outputs/expected/foo-2.txt

@@ -0,0 +1 @@
+b

test/cases/merging-multiple-outputs/expected/foo.txt

@@ -0,0 +1,2 @@
+a
+b

test/cases/merging-multiple-outputs/foo-1.js

@@ -0,0 +1,3 @@
+require.ensure([], () => {
+  require('./a.txt');
+});

test/cases/merging-multiple-outputs/foo-2.js

@@ -0,0 +1,3 @@
+require.ensure([], () => {
+  require('./b.txt');
+});

test/cases/merging-multiple-outputs/webpack.config.js

@@ -0,0 +1,24 @@
+import ExtractTextPlugin from '../../../src/index';
+
+module.exports = {
+  entry: {
+    'foo-1': './foo-1',
+    'foo-2': './foo-2',
+    'bar-1': './bar-1',
+    'bar-2': './bar-2',
+  },
+  plugins: [
+    new ExtractTextPlugin({
+      filename: '[name].txt',
+      allChunks: true,
+      merge: [{
+        filename: 'foo.txt',
+        test: /foo/,
+        originals: true,
+      }, {
+        filename: 'bar.txt',
+        test: /bar/,
+      }]
+    }),
+  ],
+};