optional externals

sokra · sokra · commit 51046618551c · 2014-07-03T00:00:06.000+02:00
track optional modules optional externals for UMD and root fixes webpack#339
diff --git a/lib/Compilation.js b/lib/Compilation.js
@@ -228,6 +228,10 @@ Compilation.prototype.addModuleDependencies = function(module, dependencies, bai
 			if(!newModule) { // from cache
 				dependantModule = this.getModule(dependantModule);
 
+				if(dependantModule.optional) {
+					dependantModule.optional = isOptional();
+				}
+
 				if(dependantModule.id === 0) {
 					return errorOrWarningAndCallback(
 						new ModuleNotFoundError(module, new Error("a dependency to an entry point is not allowed"))
@@ -257,6 +261,7 @@ Compilation.prototype.addModuleDependencies = function(module, dependencies, bai
 					newModule.profile = dependantModule.profile;
 				}
 
+				newModule.optional = isOptional();
 				newModule.issuer = dependantModule.issuer;
 				dependantModule = newModule;
 
@@ -272,6 +277,8 @@ Compilation.prototype.addModuleDependencies = function(module, dependencies, bai
 				}
 			}
 
+			dependantModule.optional = isOptional();
+
 			dependencies.forEach(function(dep) {
 				dep.module = dependantModule;
 				dependantModule.addReason(module, dep);
diff --git a/lib/ExternalModule.js b/lib/ExternalModule.js
@@ -5,6 +5,7 @@
 var Module = require("./Module");
 var OriginalSource = require("webpack-core/lib/OriginalSource");
 var RawSource = require("webpack-core/lib/RawSource");
+var WebpackMissingModule = require("./dependencies/WebpackMissingModule");
 
 function ExternalModule(request, type) {
 	Module.call(this);
@@ -61,10 +62,18 @@ ExternalModule.prototype.source = function(dependencyTemplates, outputOptions, r
 		break;
 	case "amd":
 	case "umd":
-		str = "module.exports = __WEBPACK_EXTERNAL_MODULE_" + this.id + "__;";
+		str = "";
+		if(this.optional) {
+			str += "if(typeof __WEBPACK_EXTERNAL_MODULE_" + this.id + "__ === 'undefined') {" + WebpackMissingModule.moduleCode(request) + "}\n";
+		}
+		str += "module.exports = __WEBPACK_EXTERNAL_MODULE_" + this.id + "__;";
 		break;
 	default:
-		str = "module.exports = " + request + ";";
+		str = "";
+		if(this.optional) {
+			str += "if(typeof " + request + " === 'undefined') {" + WebpackMissingModule.moduleCode(request) + "}\n";
+		}
+		str += "module.exports = " + request + ";";
 		break;
 	}
 	if(this.useSourceMap) {
diff --git a/lib/Stats.js b/lib/Stats.js
@@ -121,6 +121,7 @@ Stats.prototype.toJson = function toJson(options, forToString) {
 			size: module.size(),
 			cacheable: !!module.cacheable,
 			built: !!module.built,
+			optional: !!module.optional,
 			prefetched: !!module.prefetched,
 			chunks: module.chunks.map(function(chunk) {
 				return chunk.id;
@@ -409,6 +410,9 @@ Stats.jsonToString = function jsonToString(obj, useColors) {
 		if(!module.cacheable) {
 			red(" [not cacheable]");
 		}
+		if(!module.optional) {
+			yellow(" [optional]");
+		}
 		if(module.built) {
 			green(" [built]");
 		}
diff --git a/lib/UmdMainTemplatePlugin.js b/lib/UmdMainTemplatePlugin.js
@@ -54,9 +54,13 @@ UmdMainTemplatePlugin.prototype.apply = function(mainTemplate) {
 				var request = m.request;
 				if(typeof request === "object") request = request[type];
 				if(Array.isArray(request)) {
-					return "require(" + JSON.stringify(request[0]) + ")" + accessorToObjectAccess(request.slice(1));
+					var expr = "require(" + JSON.stringify(request[0]) + ")" + accessorToObjectAccess(request.slice(1));
 				} else 
-					return "require(" + JSON.stringify(request) + ")";
+					var expr = "require(" + JSON.stringify(request) + ")";
+				if(m.optional) {
+					expr = "(function webpackLoadOptionalExternalModule() { try { return " + expr + "; } catch(e) {} }())";
+				}
+				return expr;
 			}).join(", "));
 		}
 		var externalsArguments = externals.map(function(m) {
diff --git a/lib/dependencies/WebpackMissingModule.js b/lib/dependencies/WebpackMissingModule.js
@@ -3,16 +3,21 @@
 	Author Tobias Koppers @sokra
 */
 exports.module = function(request) {
-	return "!(function webpackMissingModule() { "+
-		"var e = new Error(" + JSON.stringify("Cannot find module \"" + request + "\"") + "); "+
-		"e.code = 'MODULE_NOT_FOUND'; "+
-		"throw e; "+
-		"}())";
+	return "!(function webpackMissingModule() { " +
+		exports.moduleCode(request) +
+		" }())";
 };
+
+exports.moduleCode = function(request) {
+	return "var e = new Error(" + JSON.stringify("Cannot find module \"" + request + "\"") + "); " +
+		"e.code = 'MODULE_NOT_FOUND'; " +
+		"throw e;";
+};
+
 exports.moduleMetaInfo = function(request) {
 	return "!(function webpackMissingModuleMetaInfo() { "+
 		"var e = new Error(" + JSON.stringify("Module cannot be imported because no meta info about exports is available \"" + request + "\"") + "); "+
 		"e.code = 'MODULE_NOT_FOUND'; "+
 		"throw e; "+
 		"}())";
-};
+};
diff --git a/test/configCases/externals/optional-externals-cjs/index.js b/test/configCases/externals/optional-externals-cjs/index.js
@@ -0,0 +1,10 @@
+it("should not fail on optional externals", function() {
+	try {
+		require("external");
+	} catch(e) {
+		e.should.be.instanceof(Error);
+		e.code.should.be.eql("MODULE_NOT_FOUND");
+		return;
+	}
+	throw new Error("It doesn't fail");
+});
diff --git a/test/configCases/externals/optional-externals-cjs/webpack.config.js b/test/configCases/externals/optional-externals-cjs/webpack.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	output: {
+		libraryTarget: "commonjs2"
+	},
+	externals: {
+		external: "external"
+	}
+};
diff --git a/test/configCases/externals/optional-externals-root/index.js b/test/configCases/externals/optional-externals-root/index.js
@@ -0,0 +1,10 @@
+it("should not fail on optional externals", function() {
+	try {
+		require("external");
+	} catch(e) {
+		e.should.be.instanceof(Error);
+		e.code.should.be.eql("MODULE_NOT_FOUND");
+		return;
+	}
+	throw new Error("It doesn't fail");
+});
diff --git a/test/configCases/externals/optional-externals-root/webpack.config.js b/test/configCases/externals/optional-externals-root/webpack.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	output: {
+		libraryTarget: "var"
+	},
+	externals: {
+		external: "external"
+	}
+};
diff --git a/test/configCases/externals/optional-externals-umd/index.js b/test/configCases/externals/optional-externals-umd/index.js
@@ -0,0 +1,10 @@
+it("should not fail on optional externals", function() {
+	try {
+		require("external");
+	} catch(e) {
+		e.should.be.instanceof(Error);
+		e.code.should.be.eql("MODULE_NOT_FOUND");
+		return;
+	}
+	throw new Error("It doesn't fail");
+});
diff --git a/test/configCases/externals/optional-externals-umd/webpack.config.js b/test/configCases/externals/optional-externals-umd/webpack.config.js
@@ -0,0 +1,8 @@
+module.exports = {
+	output: {
+		libraryTarget: "umd"
+	},
+	externals: {
+		external: "external"
+	}
+};
