Angular测试报错：‘User[]’无法赋值给‘Expected<User>’求助

错误根源 #

1. 类型不匹配：测试中user被定义为User[]数组类型，但getUserById方法返回的是单个User对象的Observable，导致expect(res).toBe(user)时出现类型赋值错误。
2. 断言方法误用：toBe用于比较引用类型的内存地址，而你需要比较的是对象的内容，应该使用toEqual做深度内容比对。

修改步骤 #

1. 修正user变量类型 #

将测试里的数组类型改为单个User对象：

const user: User = {
  "id": 23556,
  "name": "unique Ramakrishna",
  "email": "new.ramakrishna@15ce.com",
  "gender": "male",
  "status": "active"
}

2. 替换断言方法 #

把toBe换成toEqual，确保比对对象的实际内容：

userService.getUserById(id).subscribe((res) => {
  expect(res).toEqual(user);
});

修改后的完整测试代码 #

it('should call getUsersById', () => {
  const user: User = {
    "id": 23556,
    "name": "unique Ramakrishna",
    "email": "new.ramakrishna@15ce.com",
    "gender": "male",
    "status": "active"
  }

  userService.APIkey = '89668b2e3000a3aab5860410aa59fdc6c98977afa03a15d19df6be0e22f91650'
  let APIkey = userService.APIkey
  let url = 'https://gorest.co.in/public/v2/users'
  let id = 23556
  
  userService.getUserById(id).subscribe((res) => {
    expect(res).toEqual(user);
  });

  const req = httpTestingController.expectOne({
    method: 'GET',
    url: `${url}/${id}?access-token=${APIkey}`,
  });

  req.flush(user);
});

内容的提问来源于stack exchange，提问作者user19761134