fix: don't extract from common async chunks (#508)

index.js

@@ -19,11 +19,15 @@ function ExtractTextPluginCompilation() {
 	this.modulesByIdentifier = {};
 }
 
+function isInitialOrHasNoParents(chunk) {
+        return chunk.isInitial() || chunk.parents.length === 0;
+}
+
 ExtractTextPlugin.prototype.mergeNonInitialChunks = function(chunk, intoChunk, checkedChunks) {
 	if(!intoChunk) {
 		checkedChunks = [];
 		chunk.chunks.forEach(function(c) {
-			if(c.isInitial()) return;
+			if(isInitialOrHasNoParents(c)) return;
 			this.mergeNonInitialChunks(c, chunk, checkedChunks);
 		}, this);
 	} else if(checkedChunks.indexOf(chunk) < 0) {
@@ -33,7 +37,7 @@ ExtractTextPlugin.prototype.mergeNonInitialChunks = function(chunk, intoChunk, c
 			module.addChunk(intoChunk);
 		});
 		chunk.chunks.forEach(function(c) {
-			if(c.isInitial()) return;
+			if(isInitialOrHasNoParents(c)) return;
 			this.mergeNonInitialChunks(c, intoChunk, checkedChunks);
 		}, this);
 	}
@@ -262,7 +266,7 @@ ExtractTextPlugin.prototype.apply = function(compiler) {
 			});
 			async.forEach(chunks, function(chunk, callback) {
 				var extractedChunk = extractedChunks[chunks.indexOf(chunk)];
-				var shouldExtract = !!(options.allChunks || chunk.isInitial());
+				var shouldExtract = !!(options.allChunks || isInitialOrHasNoParents(chunk));
 				async.forEach(chunk.modules.slice(), function(module, callback) {
 					var meta = module[NS];
 					if(meta && (!meta.options.id || meta.options.id === id)) {
@@ -298,11 +302,11 @@ ExtractTextPlugin.prototype.apply = function(compiler) {
 			}, function(err) {
 				if(err) return callback(err);
 				extractedChunks.forEach(function(extractedChunk) {
-					if(extractedChunk.isInitial())
+					if(isInitialOrHasNoParents(extractedChunk))
 						this.mergeNonInitialChunks(extractedChunk);
 				}, this);
 				extractedChunks.forEach(function(extractedChunk) {
-					if(!extractedChunk.isInitial()) {
+					if(!isInitialOrHasNoParents(extractedChunk)) {
 						extractedChunk.modules.slice().forEach(function(module) {
 							extractedChunk.removeModule(module);
 						});

test/cases/common-async/a.js

@@ -0,0 +1,2 @@
+require("./a.txt");
+require("./b.txt");

test/cases/common-async/a.txt

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

test/cases/common-async/b.js

@@ -0,0 +1,3 @@
+require("./a.txt");
+require("./c.txt");
+

test/cases/common-async/b.txt

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

test/cases/common-async/c.txt

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

test/cases/common-async/expected/file.css

@@ -0,0 +1,3 @@
+a
+b
+c

test/cases/common-async/index.js

@@ -0,0 +1,14 @@
+require.ensure(
+	[],
+	function() {
+		require("./a.js");
+	},
+	'async-chunk-a'
+);
+require.ensure(
+	[],
+	function() {
+		require("./b.js");
+	},
+	'async-chunk-b'
+);

test/cases/common-async/webpack.config.js

@@ -0,0 +1,17 @@
+var webpack = require('webpack');
+var ExtractTextPlugin = require("../../../index");
+
+module.exports = {
+	entry: "./index",
+	plugins: [
+		new webpack.optimize.CommonsChunkPlugin({
+			name: 'common',
+			filename: 'common.js',
+			chunks: ['async-chunk-a', 'async-chunk-b']
+		}),
+		new ExtractTextPlugin({
+			filename: "file.css",
+			allChunks: true
+		})
+	]
+};