Firebase功能：编写单元测试时不能对存储进行存根

Question

我在index.js中有以下函数代码：

var admin = require('firebase-admin');
admin.initializeApp();
admin.storage();

以及以下测试代码：

var assert = require('assert');
var sinon = require('sinon');
describe('Event Sourcing', function() {
  var myFunctions, adminInitStub, adminStorageStub,admin;

  before(() => {
    admin =  require('firebase-admin');
    adminStorageStub = sinon.stub(admin, 'storage');
    adminInitStub = sinon.stub(admin, 'initializeApp');

    myFunctions = require('../index');
  });

  after(() => {
    // Restoring our stubs to the original methods.
    adminInitStub.restore();
    adminStorageStub.restore();
  });

  describe('CREATED', function() {
      it('should return -1 when the value is not present', function() {
            assert.equal(-1, [1,5,3].indexOf(4));
          });
    });
});

由于某些奇怪的原因，我不断收到以下错误，Error: The default Firebase app does not exist. Make sure you call initializeApp() before using any of the Firebase services.但我显然已经将其存根了。为什么存根只对initializeApp（）有效，而对storage（）无效。

谢谢！

Answer 1

admin.storage() 实际上是吸气剂，因此需要用这种方法

adminStorageStub = sinon.stub(admin, 'storage').get(() => {
  return () => {
    return {bucket: (() => {})};
  }
});

有关sinon存根的更多信息，请参见http://sinonjs.org/releases/v2.0.0/stubs/