added async chunk loading for node.js build

Author: sokra

lib/WebpackOptionsApply.js

@@ -78,10 +78,11 @@ WebpackOptionsApply.prototype.process = function(options, compiler) {
 		);
 		break;
 	case "node":
+	case "async-node":
 		var NodeTemplatePlugin = require("./node/NodeTemplatePlugin");
 		var NodeTargetPlugin = require("./node/NodeTargetPlugin");
 		compiler.apply(
-			new NodeTemplatePlugin(options.output),
+			new NodeTemplatePlugin(options.output, options.target === "async-node"),
 			new FunctionModulePlugin(options.context, options.output),
 			new NodeTargetPlugin()
 		);

lib/node/NodeMainTemplate.js

@@ -5,8 +5,9 @@
 var MainTemplate = require("../MainTemplate");
 var Template = require("../Template");
 
-function NodeMainTemplate(outputOptions) {
+function NodeMainTemplate(outputOptions, asyncChunkLoading) {
 	MainTemplate.call(this, outputOptions);
+	this.asyncChunkLoading = asyncChunkLoading;
 }
 module.exports = NodeMainTemplate;
 
@@ -35,25 +36,63 @@ NodeMainTemplate.prototype.renderLocalVars = function(hash, chunk) {
 NodeMainTemplate.prototype.renderRequireEnsure = function(hash, chunk) {
 	var filename = this.outputOptions.filename || "bundle.js";
 	var chunkFilename = this.outputOptions.chunkFilename || "[id]." + filename;
-	return [
-		"// \"1\" is the signal for \"already loaded\"",
-		"if(!installedChunks[chunkId]) {",
-		this.indent([
-			"var chunk = require(" +
-				JSON.stringify("./" + chunkFilename
-					.replace(Template.REGEXP_HASH, hash)
-					.replace(Template.REGEXP_NAME, ""))
-				.replace(Template.REGEXP_ID, "\" + chunkId + \"") + ");",
-			"var moreModules = chunk.modules, chunkIds = chunk.ids;",
-			"for(var moduleId in moreModules) {",
-			this.indent(this.renderAddModule(hash, chunk, "moduleId", "moreModules[moduleId]")),
-			"}",
-			"for(var i = 0; i < chunkIds.length; i++)",
-			this.indent("installedChunks[chunkIds[i]] = 1;"),
-		]),
-		"}",
-		"callback.call(null, " + this.requireFn + ");",
+	var insertMoreModules = [
+		"var moreModules = chunk.modules, chunkIds = chunk.ids;",
+		"for(var moduleId in moreModules) {",
+		this.indent(this.renderAddModule(hash, chunk, "moduleId", "moreModules[moduleId]")),
+		"}"
 	];
+	if(this.asyncChunkLoading) {
+		return [
+			"if(installedChunks[chunkId] === 1) callback.call(null, " + this.requireFn + ");",
+			"else if(!installedChunks[chunkId]) {",
+			this.indent([
+				"installedChunks[chunkId] = [callback];",
+				"var filename = __dirname + " + JSON.stringify("/" + chunkFilename
+						.replace(Template.REGEXP_HASH, hash)
+						.replace(Template.REGEXP_NAME, ""))
+					.replace(Template.REGEXP_ID, "\" + chunkId + \"") + ";",
+				"require('fs').readFile(filename, 'utf-8',  function(err, content) {",
+				this.indent([
+					"if(err) { if(" + this.requireFn + ".onerror) return " + this.requireFn + ".onerror(err); else throw err; }",
+					"var chunk = {};",
+					"require('vm').runInThisContext('(function(exports) {' + content + '\\n})', filename)(chunk);",
+				].concat(insertMoreModules).concat([
+					"var callbacks = [];",
+					"for(var i = 0; i < chunkIds.length; i++) {",
+					this.indent([
+						"if(Array.isArray(installedChunks[chunkIds[i]]))",
+						this.indent([
+							"callbacks = callbacks.concat(installedChunks[chunkIds[i]]);"
+						]),
+						"installedChunks[chunkIds[i]] = 1;"
+					]),
+					"}",
+					"for(i = 0; i < callbacks.length; i++)",
+					this.indent("callbacks[i].call(null, " + this.requireFn + ");")
+				])),
+				"});"
+			]),
+			"} else installedChunks[chunkId].push(callback);",
+		];
+	} else {
+		return [
+			"// \"1\" is the signal for \"already loaded\"",
+			"if(!installedChunks[chunkId]) {",
+			this.indent([
+				"var chunk = require(" +
+					JSON.stringify("./" + chunkFilename
+						.replace(Template.REGEXP_HASH, hash)
+						.replace(Template.REGEXP_NAME, ""))
+					.replace(Template.REGEXP_ID, "\" + chunkId + \"") + ");"
+			].concat(insertMoreModules).concat([
+				"for(var i = 0; i < chunkIds.length; i++)",
+				this.indent("installedChunks[chunkIds[i]] = 1;"),
+			])),
+			"}",
+			"callback.call(null, " + this.requireFn + ");",
+		];
+	}
 };
 
 NodeMainTemplate.prototype.renderRequireExtensions = function(hash, chunk) {

lib/node/NodeTemplatePlugin.js

@@ -5,13 +5,14 @@
 var NodeMainTemplate = require("./NodeMainTemplate");
 var NodeChunkTemplate = require("./NodeChunkTemplate");
 
-function NodeTemplatePlugin(options) {
+function NodeTemplatePlugin(options, asyncChunkLoading) {
 	this.options = options;
+	this.asyncChunkLoading = asyncChunkLoading;
 }
 module.exports = NodeTemplatePlugin;
 NodeTemplatePlugin.prototype.apply = function(compiler) {
 	var options = this.options;
-	compiler.mainTemplate = new NodeMainTemplate(options);
+	compiler.mainTemplate = new NodeMainTemplate(options, this.asyncChunkLoading);
 	compiler.chunkTemplate = new NodeChunkTemplate(options);
 	compiler.plugin("compilation", function(compilation) {
 		compilation.plugin("normal-module-loader", function(loaderContext) {