如何使用Angular 6/Jasmine对这个简单函数进行单元测试

我在我的一个组件中有以下方法。如何为它编写单元测试

 getInitialSeats() {
    for (let i = 0; i < 100; i++) {
      i = i + 1;
      this.seatObj = {
        seatName: "Seat- " + i,
        seatId: "seat_" + i
      }
      this.totalSeats.push(this.seatObj);
      this.seatObj = {};
      i = i - 1;
    }
  }

getInitialSeats（）{
for（设i=0；i<100；i++）{
i=i+1；
此.seatObj={
座位名称：“座位-”+i，
seatId:“座位”+i
}
this.totalSeats.push（this.seatObj）；
this.seatObj={}；
i=i-1；
}
}

在编写单元测试之前，我建议您稍微改进一下功能。其中有一些代码是您不一定需要的。看一看这个改进的函数，它做了完全相同的事情

getInitialSeats() {
  for (let i = 1; i <= 100; i++) {
    this.totalSeats.push({
      seatName: "Seat- " + i,
      seatId: "seat_" + i
    });        
  }
}

如果此函数是基于事件/交互在组件中的某个位置调用的，那么您可以设置一个间谍来检查是否成功调用了它。测试可以如下所示：

it('should test the initial seats generation', () => {
  // setup spy and check it hasn't been called yet
  const spy = spyOn(component, 'getInitialSeats').and.callThrough();
  expect(spy).not.toHaveBeenCalled();

  // do something that will invoke the function, here we just call it ourselves
  component.getInitialSeats();

  // check spy
  expect(spy).toHaveBeenCalledTimes(1);

  // test the amount of seats generated
  expect(component.totalSeats.length).toBe(100);

  // test some of the objects generated
  expect(component.totalSeats[0]).toEqual({ seatName: 'Seat-1', seatId: 'seat_1'});
  expect(component.totalSeats[99]).toEqual({ seatName: 'Seat-100', seatId: 'seat_100'});
});

---

他要求一个简单的函数。。。你在哪里看到“组件”？！例如，如果它是一个验证器？！

it('should test the initial seats generation', () => {
  // setup spy and check it hasn't been called yet
  const spy = spyOn(component, 'getInitialSeats').and.callThrough();
  expect(spy).not.toHaveBeenCalled();

  // do something that will invoke the function, here we just call it ourselves
  component.getInitialSeats();

  // check spy
  expect(spy).toHaveBeenCalledTimes(1);

  // test the amount of seats generated
  expect(component.totalSeats.length).toBe(100);

  // test some of the objects generated
  expect(component.totalSeats[0]).toEqual({ seatName: 'Seat-1', seatId: 'seat_1'});
  expect(component.totalSeats[99]).toEqual({ seatName: 'Seat-100', seatId: 'seat_100'});
});