单元测试和模拟然后是承诺中的方法

如果有一个逻辑单元需要用各种顺序的承诺进行测试，那么怎样才能实际确定then(() => {})函数中的逻辑？通过类似的设置，我会遇到第一次测试会通过但第二次测试没有通过的问题。我很好奇为什么匿名然后在执行块永远不会到达。单元测试和模拟然后是承诺中的方法

//Implementation 
class FiddleService { 
    constructor(dependencies = {}) { 
     const { someService = new SomeService() } = dependencies; 
     this.someService = someService; 
    } 

    doSomething(params) { 
     this.someService.asyncOperation1(params).then((result) => { 
      ... 
      //never gets called by spy in test 
      return this.someService.asyncOperation2(result.firstName); 
     }).then((result) => { 
      return this.someService.asyncOperation3(result.age); 
     }); 
    } 
} 
//test 
describe("FiddleService",() => { 
    let someService; 
    beforeAll(() => { 
     someService = new SomeService(); 
     spyOn(someService.asyncOperation1).and 
      .returnValue(new Promise(() => {firstName: "Jan"}); 
     spyOn(someService.asyncOperation2).and 
      .returnValue(new Promise(() => {age: 50}); 
     spyOn(someService.asyncOperation3); 
    }); 

    it("calls asyncOperation1",() => { 
     let fiddleService = new FiddleService(); 
     fiddleService.doSomething({}); 
     expect(someService.asyncOperation1).toHaveBeenCalled(); 
    }); 

    it("calls asyncOperation2",() => { 
     let fiddleService = new FiddleService(); 
     fiddleService.doSomething({}); 
     expect(someService.asyncOperation2).toHaveBeenCalled(); 
    }); 
});

来源

2017-10-20 rajh2504

这两个'new Promise（（）=> ...）'表达式返回永远不会解析的promise。 'Promise.resolve（...）'在两个地方似乎更合适。 –

作为@ roamer-1888表示该解决方案与调用承诺和在测试中完成调用有关。

//test 
describe("FiddleService",() => { 
    let someService; 
    beforeAll(() => { 
     someService = new SomeService(); 
     spyOn(someService.asyncOperation1).and 
      .returnValue(new Promise(() => {firstName: "Jan"}); 
     spyOn(someService.asyncOperation2).and 
      .returnValue(new Promise(() => {age: 50}); 
     spyOn(someService.asyncOperation3); 
    }); 

    it("calls asyncOperation1",() => { 
     let fiddleService = new FiddleService(); 
     fiddleService.doSomething({}); 
     expect(someService.asyncOperation1).toHaveBeenCalled(); 
    }); 

    it("calls asyncOperation2", (done) => { 
     let fiddleService = new FiddleService(); 
     fiddleService.doSomething({}).then(_ => { 
      expect(someService.asyncOperation2).toHaveBeenCalled(); 
      done(); 
     }); 
    }); 
});

来源

2017-10-21 04:23:55 rajh2504

我不知道我帮了很多，但嘿，很高兴得到提及，谢谢。 –

茉莉花不是我的技能集的主要部分，所以这是暂时提供。

我仍然认为你需要Promise.resolve()而不是new Promise()在两个地方，并认为你可以利用茉莉花在单个测试中处理多个expect（）的能力，而不会丢失任何信息。

//test 
describe("FiddleService",() => { 
    let someService; 
    beforeAll(() => { 
     someService = new SomeService(); 
     spyOn(someService.asyncOperation1).and.returnValue(Promise.resolve({firstName: "Jan"})); 
     spyOn(someService.asyncOperation2).and.returnValue(Promise.resolve({age: 50})); 
     spyOn(someService.asyncOperation3); 
    }); 

    it("should make three sequential async calls", (done) => { 
     let fiddleService = new FiddleService(); 
     fiddleService.doSomething({}).then(_ => { 
      expect(someService.asyncOperation1).toHaveBeenCalled(); 
      expect(someService.asyncOperation2).toHaveBeenCalled(); 
      expect(someService.asyncOperation3).toHaveBeenCalled(); 
      done(); 
     }); 
    }); 
});

来源

2017-10-22 02:16:13

单元测试和模拟然后是承诺中的方法

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