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如何监视一个函数,该函数内部有一个Promise,但不返回结果,而是处理响应本身?

es6-modules jasmine

Paul Geisler · 技术社区 · 6 年前

// Game.js

export default {
    mine: null,

    handle: function(me) {
        console.log("   FOOOOO " + me)
    },

    setSource: function() {
        this.mine.getSource().then((response) => {
          const {source} = response
          this.handle(source)
        })
    }
}

在这里我试着监视:

// GameSpec.js

import Game from '../../lib/jasmine_examples/Game'

Game.mine = {}

describe("Game", function() {
  it("should set source and handle it", function() {

    Game.mine.getSource = () => {
      return new Promise((resolve)=>{
        resolve( {
          source : 'BAAAAR'
        })
      })
    }

    spyOn(Game, 'handle').and.callThrough()

    Game.setSource()

    expect(Game.handle).toHaveBeenCalled()
  });
});

在输出中可以看到函数“handle”被调用:

Started
F   FOOOOO BAAAAR


Failures:
1) Game should set source and handle it
  Message:
    Expected spy handle to have been called.
  Stack:
    Error: Expected spy handle to have been called.
        at <Jasmine>
        at UserContext.<anonymous> (/Users/silverbook/Sites/zTest/jasmine/spec/jasmine_examples/PlayerSpec.js:20:29)
        at <Jasmine>

1 spec, 1 failure

jasmine 说没打电话来。

如果我把被嘲笑的 Promise 考试通过了,但我需要去那里。在另一个测试中,我将返回Promise中的错误并让它从另一个函数处理。

所以打破了测试但为什么?

1 回复 | 直到 6 年前

Brian Adams 6 年前

测试同步执行,并且 expect 在回调排队之前失败 this.mine.getSource().then()

为了 Jasmine >=2.7和 async 函数支持您可以将测试函数转换为 异步 函数并添加 await Promise.resolve();

对于您的测试,它将如下所示:

import Game from '../../lib/jasmine_examples/Game'

Game.mine = {}

describe("Game", function() {
  it("should set source and handle it", async () => {

    Game.mine.getSource = () => {
      return new Promise((resolve)=>{
        resolve( {
          source : 'BAAAAR'
        })
      })
    }
    spyOn(Game, 'handle').and.callThrough();

    Game.setSource();

    await Promise.resolve(); // let the event loop cycle

    expect(Game.handle).toHaveBeenCalled();
  });
});

茉莉 可以使用的版本 done() 这样地:

import Game from '../../lib/jasmine_examples/Game'

Game.mine = {}

describe("Game", function() {
  it("should set source and handle it", (done) => {

    Game.mine.getSource = () => {
      return new Promise((resolve)=>{
        resolve( {
          source : 'BAAAAR'
        })
      })
    }
    spyOn(Game, 'handle').and.callThrough();

    Game.setSource();

    Promise.resolve().then(() => {
      expect(Game.handle).toHaveBeenCalled();
      done();
    });

  });
});

Boris Yakubchik 5 年前

你可以在里面进行测试 fakeAsync tick() 在 expect()

服务:

getFirebaseDoc() {   
  this.db.firestore.doc('some-doc').get()
    .then(this.getFirebaseDocThen)
    .catch(this.getFirebaseDocCatch);
}

it('should call getFirebaseDocThen', fakeAsync(() => {          // note `fakeAsync`
    spyOn(service, 'getFirebaseDocThen');
    spyOn(service.db.firestore, 'doc').and.returnValue({
      get: (): any => {
        return new Promise((resolve: any, reject: any): any => {
          return resolve({ exists: true });
        });
      },
    });
    service.getFirebaseDoc();
    tick();                                                     // note `tick()`
    expect(service.getFirebaseDocThen).toHaveBeenCalled();
}));