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我正在学习Jest并运行到试图模拟异步函数的问题,该异步函数返回fetch
的承诺。由于未解决的承诺导致Jest失败的异步测试
在他们的文档,还有这个: “如果一个承诺不能解决所有,可能会抛出这个错误: - 错误:超时 - 异步回调不被jasmine.DEFAULT_TIMEOUT_INTERVAL.
最常见的是这个规定的超时时间内调用是由Promise实现冲突引起的,请考虑用您自己的替代全局承诺实现,例如global.Promise = require.requireActual('promise');
和/或将使用的Promise库合并为一个。“
这可能是问题,但我不清楚如何解决我的问题或确定Promise
打破。
也许我对Jest的嘲笑的理解是错误的?我试着用他们的例子,当然它工作得很好。 (https://facebook.github.io/jest/docs/tutorial-async.html#content)
这是我在控制台中:
● endpoint can receive form data › can parse and fulfill a promise
Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.
这里是我的模块和测试:
// myModule/index.js
import { OK } from 'http-status-codes';
import request from './request';
import parseForm from '../../../../modules/parseMultiPart';
export default (req, res, next) => parseForm(req)
.then(body => request(body, req)
.then(result => result.text())
.then(result => res.status(OK).send(result)))
.catch(next);
// myModule/request.js
import fetch from 'node-fetch';
export default (body, req) => fetch('http://url', {
method: 'POST',
body: JSON.stringify(body.fields),
headers: {
'Content-Type': 'application/json',
'X-Request-Id': req.id
}
});
// myModule/__tests__/myModule.test.js
import MockReq from 'mock-req';
import MockRes from 'mock-res';
import myModule from '../';
jest.mock('../request');
describe('endpoint can receive form data',() => {
const response = new MockRes();
const request = new MockReq({
method: 'POST',
url: '/webhook',
headers: {
'Content-Disposition': 'form-data; name="file"; filename="plain.txt"',
'Content-Type': 'multipart/form-data; custom=stuff; boundary=----TLV0SrKD4z1TRxRhAPUvZ',
'Content-Length': 213
}
});
it('can parse and fulfill a promise',() => myModule(request, response)
.then(text => expect(text).toEqual('API Event Received'))
);
});
// myModule/__mocks__/request.js
export default function request() {
return new Promise((resolve) => {
process.nextTick(
() => resolve('API Event Received')
);
});
}