Node.js - 内部模拟 promise 的函数单元测试

Question

我目前正在 JavaScript 制作一个小型服务器，作为学习过程的一部分，我正在为功能编写单元测试。不幸的是，我运行在处理承诺的某个测试中遇到了重大困难。下面是路由器模块，为了方便测试，有单独的handlePUT函数。

const express = require('express');
const service = require('../service/user.service');

const dutyStatusRouter = express.Router();
const output = console;

function handlePUT(req, res) {
    service.updateUserStatus()
        .then((fulfilled) => {
            res.status(fulfilled);
            res.send();
        })
        .catch(() => {
            res.status(500);
            res.send();
        });
}

dutyStatusRouter.route('/').put(handlePUT);

updateUserStatus 函数基本上切换数据库中的布尔值，看起来有点像这样：

function updateUserStatus() {
    return new Promise((resolve, reject) => {
        if (…) {
            resolve(201);
        } else if (…) {
            resolve(200);
        } else {
            reject();
        }
    });
}

至于单元测试，我使用 mocha/chai 和 proxyquire 来创建模拟 updateUserStatus。

const chai = require('chai');
const sinon = require('sinon');
const proxyquire = require('proxyquire');

const serviceStub = {};

describe('=== Unit test ===', () => {
    it('Handle PUT test: promise kept', async () => {
        const dutyStatusRouter = proxyquire('../../router/duty-status.router', {
            '../service/user.service': serviceStub,
        });
        serviceStub.updateUserStatus = () => {
            return new Promise((resolve, reject) => {
                resolve(200);
            });
        };
        const res = {
            status: sinon.fake(),
            send: sinon.fake(),
        };
        await dutyStatusRouter.handlePUT({}, res);
        chai.assert(res.status.calledOnceWith(200));
    });
});

每当我尝试运行单元测试时，我都会收到错误 Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.。如果我尝试添加 done() 它仍然会失败，并给出错误消息 Error: Resolution method is overspecified. Specify a callback *or* return a Promise; not both.

Answer 1

找到了有效的解决方案，所以我将其添加到此处：

const chai = require('chai');
const sinon = require('sinon');
const proxyquire = require('proxyquire');

const serviceStub = {};
const dutyStatusRouter = proxyquire('../../router/duty-status.router', {
    '../service/user.service': serviceStub,
});

describe('=== Unit test ===', () => {
    it('Handle PUT test: promise kept', (done) => {
        serviceStub.updateUserStatus = sinon.stub().resolves(200);
        const res = {
            status: sinon.fake(),
            send: sinon.fake(),
        };
        dutyStatusRouter.handlePUT({}, res).then(() => {
            chai.assert(res.status.calledWith(200));
            done();
        });
    });
});

注意：我稍微更改了 handlePUT 函数，现在看起来像这样（我只是添加了一个 return）：

function handlePUT(req, res) {
    return service.updateUserStatus()
        .then((fulfilled) => {
            output.log('Promise fulfilled');
            res.status(fulfilled);
            res.send();
        })
        .catch(() => {
            output.log('Promise unfulfilled');
            res.status(500);
            res.send();
        });
}

Node.js - 内部模拟 promise 的函数单元测试

Node.js - unit test for function with mocked promise inside

javascript

unit-testing

mocking

promise

proxyquire