Inline cache mock for DependencyGraph-test

Reviewed By: davidaurelio

Differential Revision: D2629211

fb-gh-sync-id: ade0bf4e486b58ecbc9a29eb3bdb61286eebb3d5

react-packager/__mocks__/debug.js

@@ -8,6 +8,4 @@
  */
 'use strict';
 
-module.exports = function() {
-  return function() {};
-};
+module.exports = () => () => {};

react-packager/src/DependencyResolver/DependencyGraph/__tests__/DependencyGraph-test.js

@@ -13,11 +13,8 @@ jest.autoMockOff();
 const Promise = require('promise');
 
 jest
-  .mock('fs')
-  .mock('../../../Cache')
-  .mock('../../../Activity');
+  .mock('fs');
 
-var Cache = require('../../../Cache');
 var DependencyGraph = require('../index');
 var fs = require('fs');
 
@@ -51,6 +48,13 @@ describe('DependencyGraph', function() {
       isWatchman: () => Promise.resolve(false),
     };
 
+    const Cache = jest.genMockFn();
+    Cache.prototype.get = jest.genMockFn().mockImplementation(
+      (filepath, field, cb) => cb(filepath)
+    );
+    Cache.prototype.invalidate = jest.genMockFn();
+    Cache.prototype.end = jest.genMockFn();
+
     defaults = {
       assetExts: ['png', 'jpg'],
       cache: new Cache(),

react-packager/src/DependencyResolver/DependencyGraph/index.js

@@ -42,7 +42,7 @@ class DependencyGraph {
     this._opts = {
       activity: activity || defaultActivity,
       roots,
-      ignoreFilePath: ignoreFilePath || () => {},
+      ignoreFilePath: ignoreFilePath || (() => {}),
       fileWatcher,
       assetRoots_DEPRECATED: assetRoots_DEPRECATED || [],
       assetExts,