improvement: add mocks helper module for test env

no issue
- add methods to mock/unmock not existent files

core/test/utils/index.js

@@ -14,6 +14,7 @@ var Promise       = require('bluebird'),
     filterData    = require('./fixtures/filter-param'),
     API           = require('./api'),
     fork          = require('./fork'),
+    mocks         = require('./mocks'),
     config        = require('../../server/config'),
 
     fixtures,
@@ -596,6 +597,8 @@ module.exports = {
     initData: initData,
     clearData: clearData,
 
+    mocks: mocks,
+
     fixtures: fixtures,
 
     DataGenerator: DataGenerator,

core/test/utils/mocks/index.js

@@ -0,0 +1 @@
+exports.utils = require('./utils');

core/test/utils/mocks/utils.js

@@ -0,0 +1,20 @@
+var Module = require('module'),
+    originalRequireFn = Module.prototype.require;
+
+/**
+ * helper fn to mock non existent modules
+ * mocks.utils.mockNotExistingModule(/pattern/, mockedModule)
+ */
+exports.mockNotExistingModule = function mockNotExistingModule(modulePath, module) {
+    Module.prototype.require = function (path) {
+        if (path.match(modulePath)) {
+            return module;
+        }
+
+        return originalRequireFn.apply(this, arguments);
+    };
+};
+
+exports.unmockNotExistingModule = function unmockNotExistingModule() {
+    Module.prototype.require = originalRequireFn;
+};