Add option to map module names to stub modules.

src/HasteModuleLoader/HasteModuleLoader.js

@@ -70,6 +70,8 @@ var NODE_CORE_MODULES = {
 
 var VENDOR_PATH = path.resolve(__dirname, '../../vendor');
 
+const hasOwnProperty = Object.prototype.hasOwnProperty;
+
 var _configUnmockListRegExpCache = null;
 
 function _buildLoadersList(config) {
@@ -152,6 +154,15 @@ function Loader(config, environment, resourceMap) {
     }
   }
 
+  // Workers communicate the config as JSON so we have to create a regex object
+  // in the module loader instance.
+  this._mappedModuleNames = Object.create(null);
+  if (this._config.moduleNameMapper.length) {
+    this._config.moduleNameMapper.forEach(
+      map => this._mappedModuleNames[map[1]] = new RegExp(map[0])
+    );
+  }
+
   this.resetModuleRegistry();
 }
 
@@ -321,6 +332,16 @@ Loader.prototype._getResource = function(resourceType, resourceName) {
     );
   }
 
+  if (
+    resource === undefined &&
+    resourceType === 'JSMock'
+  ) {
+    var moduleName = this._resolveStubModuleName(resourceName);
+    if (moduleName) {
+      resource = this._resourceMap.getResource('JS', moduleName);
+    }
+  }
+
   return resource;
 };
 
@@ -556,17 +577,16 @@ Loader.prototype._nodeModuleNameToPath = function(currPath, moduleName) {
  */
 Loader.prototype._shouldMock = function(currPath, moduleName) {
   var moduleID = this._getNormalizedModuleID(currPath, moduleName);
-  if (this._builtInModules.hasOwnProperty(moduleName)) {
+  if (hasOwnProperty.call(this._builtInModules, moduleName)) {
     return false;
-  } else if (this._explicitShouldMock.hasOwnProperty(moduleID)) {
+  } else if (hasOwnProperty.call(this._explicitShouldMock, moduleID)) {
     return this._explicitShouldMock[moduleID];
   } else if (NODE_CORE_MODULES[moduleName]) {
     return false;
   } else if (this._shouldAutoMock) {
-
     // See if the module is specified in the config as a module that should
     // never be mocked
-    if (this._configShouldMockModuleNames.hasOwnProperty(moduleName)) {
+    if (hasOwnProperty.call(this._configShouldMockModuleNames, moduleName)) {
       return this._configShouldMockModuleNames[moduleName];
     } else if (this._unmockListRegExps.length > 0) {
       this._configShouldMockModuleNames[moduleName] = true;
@@ -906,6 +926,23 @@ Loader.prototype.requireModule = function(currPath, moduleName,
   return moduleObj.exports;
 };
 
+/**
+ * If the moduleNameMapper config is set, go through all the mappings
+ * and resolve the module name.
+ *
+ * @param string moduleName
+ * @param string the resolved module name
+ */
+Loader.prototype._resolveStubModuleName = function(moduleName) {
+  var nameMapper = this._mappedModuleNames;
+  for (let mappedModuleName in nameMapper) {
+    var regex = nameMapper[mappedModuleName];
+    if (regex.test(moduleName)) {
+      return mappedModuleName;
+    }
+  }
+};
+
 /**
  * Given a module name, return either the real module or the mock version of
  * that module -- depending on the mocking state of the loader (and, perhaps

src/HasteModuleLoader/__tests__/HasteModuleLoader-hasDependency-test.js

@@ -15,7 +15,8 @@ describe('nodeHasteModuleLoader', function() {
   var mockEnvironment;
   var resources;
   var mockConfig = {
-    coverageCollector: '../IstanbulCollector'
+    coverageCollector: '../IstanbulCollector',
+    moduleNameMapper: [],
   };
 
   var mockResourceMap = {

src/HasteModuleLoader/__tests__/HasteModuleLoader-requireModuleOrMock-test.js

@@ -20,7 +20,11 @@ describe('HasteModuleLoader', function() {
 
   var CONFIG = utils.normalizeConfig({
     name: 'HasteModuleLoader-tests',
-    rootDir: path.resolve(__dirname, 'test_root')
+    rootDir: path.resolve(__dirname, 'test_root'),
+    moduleNameMapper: {
+      '^image![a-zA-Z0-9$_-]+$': 'GlobalImageStub',
+      '^[./a-zA-Z0-9$_-]+\.png$': 'RelativeImageStub',
+    },
   });
 
   function buildLoader() {
@@ -92,5 +96,20 @@ describe('HasteModuleLoader', function() {
         expect(exports.isManualMockModule).toBe(false);
       });
     });
+
+    pit('resolves mapped module names and unmocks them by default', function() {
+      return buildLoader().then(function(loader) {
+        loader.requireModuleOrMock(__filename, 'jest-runtime');
+        var exports =
+          loader.requireModuleOrMock(__filename, 'image!not-really-a-module');
+        expect(exports.isGlobalImageStub).toBe(true);
+
+        exports = loader.requireModuleOrMock(__filename, 'cat.png');
+        expect(exports.isRelativeImageStub).toBe(true);
+
+        exports = loader.requireModuleOrMock(__filename, 'dog.png');
+        expect(exports.isRelativeImageStub).toBe(true);
+      });
+    });
   });
 });

src/HasteModuleLoader/__tests__/test_root/GlobalImageStub.js

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule GlobalImageStub
+ */
+
+'use strict';
+
+exports.isGlobalImageStub = true;

src/HasteModuleLoader/__tests__/test_root/RelativeImageStub.js

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2014, Facebook, Inc. All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule RelativeImageStub
+ */
+
+'use strict';
+
+exports.isRelativeImageStub = true;

src/lib/utils.js

@@ -23,6 +23,7 @@ var DEFAULT_CONFIG_VALUES = {
   moduleLoader: require.resolve('../HasteModuleLoader/HasteModuleLoader'),
   preprocessorIgnorePatterns: [],
   modulePathIgnorePatterns: [],
+  moduleNameMapper: [],
   testDirectoryName: '__tests__',
   testEnvironment: require.resolve('../JSDomEnvironment'),
   testEnvData: {},
@@ -207,6 +208,13 @@ function normalizeConfig(config) {
         ));
         break;
 
+      case 'moduleNameMapper':
+        value = Object.keys(config[key]).map(regex => [
+          regex,
+          _replaceRootDirTags(config.rootDir, config[key][regex])
+        ]);
+        break;
+
       case 'preprocessorIgnorePatterns':
       case 'testPathIgnorePatterns':
       case 'modulePathIgnorePatterns':