Promise 的 Mocha 单元测试抛出错误

Question

我正在尝试对 Promise 进行单元测试。这是代码：

it('it should return some 10 user data with ok status code when called with url ', (done) => {
    return user.getUsers('https://jsonplaceholder.typicode.com/users')
    .then((response) => {
        console.log('me here')
        assert.equal(JSON.parse(response).length, 10)
    })
    .catch((err)=>{
        console.log('me in error')
        assert.fail('err')
    })
})

以上代码在运行时抛出以下错误： Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (C:\Users\ajay\jay-workspace\UniTestModule\test\user.test.js)

Answer 1

您应该在使用异步测试时调用 done() 回调（有关详细信息，请查看 https://mochajs.org/#asynchronous-code）。

it('it should return some 10 user data with ok status code when called with url ', (done) => {
user.getUsers('https://jsonplaceholder.typicode.com/users')
.then((response) => {
    console.log('me here')
    assert.equal(JSON.parse(response).length, 10);
    done();
})
.catch((err)=>{
    console.log('me in error')
    assert.fail('err');
    done(err);
})

Answer 2

done 未被调用，这导致测试超时。

Mocha 原生支持 promises。 done 不应该在有承诺时使用；相反，应返回承诺：

it('it should return some 10 user data with ok status code when called with url ', () => {
    return user.getUsers('https://jsonplaceholder.typicode.com/users')
    .then((response) => {
        console.log('me here')
        assert.equal(JSON.parse(response).length, 10)
    });
})

拒绝的承诺将无法通过测试，也不需要assert.fail。

Answer 3

你应该使用 --timeout hook 并像 ./node_module/.bin/mocha test/ --timeout=5000 一样增加毫秒数或者您可以在测试用例正文中添加 this.timeout(5000)

it('it should return some 10 user data with ok status code when called with url ', (done) => {
user.getUsers('https://jsonplaceholder.typicode.com/users')
.then((response) => {
    console.log('me here')
    assert.equal(JSON.parse(response).length, 10);
    this.timeout(5000);
    setTimeout(done, 3000);
})

https://mochajs.org/#test-level

Promise 的 Mocha 单元测试抛出错误

Mocha unit test for Promise throws error

unit-testing

mocha.js

node.js