如何在 Firebase Cloud Functions 测试中模拟 FCM admin.messaging().sendToDevice() 的实现

Question

我无法在 Typescript for Firebase Cloud Functions 中模拟 Firebase 消息传递函数。我正在使用firebase-functions-test Companion SDK 来构建docs 中提到的在线测试。我正在使用 jest mocks 来模拟 admin.messaging().sendToDevice 函数。

const fcmMock = jest.spyOn(admin.messaging(),'sendToDevice');

fcmMock.mockImplementation(async (registrationToken: string | string[], payload: admin.messaging.MessagingPayload, options?: admin.messaging.MessagingOptions)=>{
      console.log('FCM Mock called with message: '+payload.notification+'\nToken ids:'+registrationToken);
      return new Promise<admin.messaging.MessagingDevicesResponse>(undefined);
}); 

因为返回类型对象MessagingDevicesResponse>(undefined) 需要一个复杂的参数，所以运行它会得到以下错误：

'undefined' 类型的参数不能分配给 '(resolve: (value?: MessagingDevicesResponse | PromiseLike | undefined) => void, reject: (reason?: any) => void) => void' 类型的参数.

我要测试的代码：

export async function cleanupToken(response: admin.messaging.MessagingDevicesResponse, userDataSnapshot:FirebaseFirestore.DocumentSnapshot) {
    // For each notification we check if there was an error.
    if(response.results.length>0){
        const error = response.results[0].error;
        if (error) {
            // Cleanup the tokens who are not registered anymore.
            // Error Codes: https://firebase.google.com/docs/cloud-messaging/send-message#admin_sdk_error_reference
            if (error.code === 'messaging/invalid-registration-token' ||
                error.code === 'messaging/registration-token-not-registered') {
                // Some Logic here to cleanup the token and mark the user
                }
            }
        }
    }
}

Answer 1

查看您的代码有一些缺失/不正确的地方：

1. 更改 jest.spyOn(admin.messaging(),'sendToDevice'); to jest.spyOn(admin,'sendToDevice');

2. 传入模拟对象，在本例中是响应和快照

   // A fake response object, with a send to test the response
   const res = {
         send: (response) => {
             expect(response).toBe("Hello from Firebase!");
             done();
             }
         };
   
   //how to create a datasnapshot. Takes in 2 parameters, the object and the reference path
   const userDataSnapshot = test.database.makeDataSnapshot(Object,'ref/to-the/path');
   

3. 您不会在开玩笑的测试用例中返回承诺，而是使用开玩笑的测试方法（在这种情况下是预期的）。

4. 通常开玩笑的测试（在这种情况下是预期的）可以在函数中完成，但我们在响应中执行它，因为这是回调，因此它发生在最后。

   李>

你的测试用例应该是这样的：

describe('testing jest functions',() =>{
  let index,adminStub;


  //setup test enviroment
  beforeAll(() =>{
      adminStub = jest.spyOn(admin, "initializeApp");
      index = require('./index');

      return;
  });

  //tear down
  afterAll(() =>{
    adminStub.mockRestore();
    testEnv.cleanup();
  });

  it('test cleanupToken function', (done) =>{

        const res = {
              send: (response) => {
                    //assuming you use response.send in your actual code you can test it
                  expect(response).toBe("Hello from Firebase!");
                  done();
                  }
              };

        const userDataSnapshot = test.database.makeDataSnapshot(Object,'ref/to-the/path');

      index.cleanupToken(res,userDataSnapshot);
  });