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我正在學習Jest並運行到試圖模擬異步函數的問題,該異步函數返回fetch
的承諾。由於未解決的承諾導致Jest失敗的異步測試
在他們的文檔,還有這個: 「如果一個承諾不能解決所有,可能會拋出這個錯誤: - 錯誤:超時 - 異步回調不被jasmine.DEFAULT_TIMEOUT_INTERVAL.
最常見的是這個規定的超時時間內調用是由Promise實現衝突引起的,請考慮用您自己的替代全局承諾實現,例如global.Promise = require.requireActual('promise');
和/或將使用的Promise庫合併爲一個。「
這可能是問題,但我不清楚如何解決我的問題或確定Promise
打破。
也許我對Jest的嘲笑的理解是錯誤的?我試着用他們的例子,當然它工作得很好。 (https://facebook.github.io/jest/docs/tutorial-async.html#content)
這是我在控制檯中:
● 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.
這裏是我的模塊和測試:
// 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')
);
});
}