你能编写期望throw的异步测试吗?

我正在写一个async测试，期望async函数抛出像这样:

it("expects to have failed", async () => {
  let getBadResults = async () => {
    await failingAsyncTest()
  }
  expect(await getBadResults()).toThrow()
})

但玩笑只是失败而不是通过测试:

 FAIL  src/failing-test.spec.js
  ● expects to have failed

    Failed: I should fail!

如果我重写这个测试，看起来像这样:

expect(async () => {
  await failingAsyncTest()
}).toThrow()

我得到这个错误，而不是通过测试:

expect(function).toThrow(undefined)

Expected the function to throw an error.
But it didn't throw anything.

当前回答

为了能够创建许多测试条件，而不必每次都解析承诺，这也可以工作:

it('throws an error when it is not possible to create an user', async () => {
        const throwingFunction = () => createUser(createUserPayload)

        // This is what prevents the test to succeed when the promise is resolved and not rejected
        expect.assertions(3)

        await throwingFunction().catch(error => {
            expect(error).toBeInstanceOf(Error)
            expect(error.message).toMatch(new RegExp('Could not create user'))
            expect(error).toMatchObject({
                details: new RegExp('Invalid payload provided'),
            })
        })
    })

2022-04-25 19:26:57

其他回答

自定义错误类

废品的使用。toThrow对你不起作用。相反，您可以将rejects方法与toBeInstanceOf匹配器结合起来，以匹配已抛出的自定义错误。

例子

it("should test async errors", async () => {
  await expect(asyncFunctionWithCustomError()).rejects.toBeInstanceOf(
    CustomError
  )
})

2021-09-06 11:05:21

我一直在测试Firebase的云功能，这是我得出的结论:

test("It should test async on failing cloud functions calls", async () => {
    await expect(async ()=> {
        await failingCloudFunction(params)
    })
    .rejects
    .toThrow("Invalid type"); // This is the value for my specific error
  });

这是建立在丽桑德罗的答案之上的。

2021-08-19 14:45:55

我想在此基础上补充一点，说明您正在测试的函数必须抛出一个实际的Error对象抛出新的Error(…)。Jest似乎不能识别你是否抛出了一个像throw ' an error occurred!'这样的表达式。

2019-08-01 16:25:34

test("它应该在云函数调用失败时测试async "， async () => { failingCloudFunction (params)。Catch (e => { 期望(e.message)。托比(无效的类型) }） })；

2022-03-14 19:39:31

为了能够创建许多测试条件，而不必每次都解析承诺，这也可以工作:

it('throws an error when it is not possible to create an user', async () => {
        const throwingFunction = () => createUser(createUserPayload)

        // This is what prevents the test to succeed when the promise is resolved and not rejected
        expect.assertions(3)

        await throwingFunction().catch(error => {
            expect(error).toBeInstanceOf(Error)
            expect(error.message).toMatch(new RegExp('Could not create user'))
            expect(error).toMatchObject({
                details: new RegExp('Invalid payload provided'),
            })
        })
    })

2022-04-25 19:26:57

你能编写期望throw的异步测试吗?

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