测试有效的 objectId

Question

我正在使用 jest 来测试一个 mongoDB ObjectID。 在函数中，我检查 id 是否有效。然后我返回 ObjectId。

在我的测试中，我希望使用 ObjectId 的valueOf() 获得一个字符串，但测试失败了：

import { ObjectId } from 'mongodb'

const safeObjectId = (id) => {
  return ObjectId.isValid(id) ? new ObjectId(id) : null
}

it('should return ObjectId if it is valid', () => {
  const result = safeObjectId('5a1154523a6bcc1d245e143d')
  expect(typeof result).toBe('object')
  expect(result.valueOf()).toEqual('5a1154523a6bcc1d245e143d')
})

但我确实得到了错误

Expected value to equal:
  "5a1154523a6bcc1d245e143d"
Received:
  "5a1154523a6bcc1d245e143d"

Difference:
  Comparing two different types of values. Expected string but received object.

Answer 1

你需要访问'str'属性：

const safeObjectId = (id) => {
  return ObjectId.isValid(id) ? new ObjectId(id) : null
}

it('should return ObjectId if it is valid', () => {
  const result = safeObjectId('5a1154523a6bcc1d245e143d')
  expect(typeof result).toBe('object')
  expect(result.str).toEqual('5a1154523a6bcc1d245e143d')
})

来自文档...https://docs.mongodb.com/manual/reference/method/ObjectId/

访问 ObjectId() 对象的 str 属性，如下：

ObjectId("507f191e810c19729de860ea").str

附言在单个测试中有多个断言是不好的做法，我会将对象检查和值检查移动到两个单独的测试中，就像这样......

const safeObjectId = (id) => {
  return ObjectId.isValid(id) ? new ObjectId(id) : null
}

it('should return an object', () => {
  const result = safeObjectId('5a1154523a6bcc1d245e143d')
  expect(typeof result).toBe('object')
})

it('should return the correct ObjectId', () => {
  const result = safeObjectId('5a1154523a6bcc1d245e143d')
  expect(result.str).toEqual('5a1154523a6bcc1d245e143d')
})