如何测试一个函数(节点模块)，如果它被调用，如果它被用柴间谍/摩卡/测试调用

Question

我想测试是否使用chai-spies调用函数。

这是我想要测试的类

index.js

const express = require('express');
const router = express.Router();
const request = require('request');
router.post('/login',(req,res) => {
const {username, password} = req.body;
let login= {};
login.username= username;
login.password= password;
try{
request.post({    // <---- this is the function I want to test if its called
header: {'Content-Type': 'application/json-patch+json', 'accept ': 'application/json'},
url: ' https://exmple',
json: login
}, function (error, response, body) {
// implementation
});
} catch (error) {
console.log(error);
}
});
module.exports = router;

下面是我试着写的测试文件

index.test.js

const route = require ("../routes/index");
const spy = chai.spy.on(route,'request');
const request = require("supertest");
const express = require("express");
const bodyParser = require('body-parser');
const chai = require('chai');
let spies = require('chai-spies');
chai.use(spies);
const expect = chai.expect;
//create app without credentials
let app = express();
app.use(express.urlencoded({ extended: false }));
app.set('view engine', 'ejs');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));
app.use(route);
describe("Testing the POST /login route", () => {
let spy = chai.spy.on(route,'request'); // I tried to mock the function here with chai spies.
it('should make a request to backend server when form is filled, but with wrong credentials', (done) => 
{
request(app)
.post('/login')
.set('Accept', 'application/json')
.send({username:"test",password:"test"})
.end(function (err,res) {   
expect(spy).to.have.been.called.once;
done();
});
});
});

正如你所看到的，我试图用猜间谍来模拟请求功能let spy=chai.spy.on(route，'request'(

但当我运行代码时，它确实识别出了mocking函数并返回

Uncaught AssertionError: expected { Spy 'object.request' } to have been called once but got 0
+ expected - actual
-0
+1

如果调用了请求函数，我该如何测试它。该请求实际上是一个节点模块，用于在另一个后端服务器上进行http调用。

谢谢你的帮助。

Answer 1

您没有正确地模拟request.post方法。此外，您应该实现/login路由的控制器，这意味着您需要使用res.send()、res.json()或res.end()向客户端发送一些数据。否则，超级测试客户端将不会得到响应，它将使测试用例超时。

这里有一个例子：

index.js:

const express = require('express');
const router = express.Router();
const request = require('request');
router.post('/login', (req, res) => {
const { username, password } = req.body;
let login = {};
login.username = username;
login.password = password;
try {
request.post(
{
header: { 'Content-Type': 'application/json-patch+json', 'accept ': 'application/json' },
url: ' https://exmple',
json: login,
},
function(error, response, body) {
res.send('implementation');
},
);
} catch (error) {
console.log(error);
}
});
module.exports = router;

index.test.js:

const route = require('./');
const request = require('request');
const supertest = require('supertest');
const express = require('express');
const bodyParser = require('body-parser');
const chai = require('chai');
let spies = require('chai-spies');
chai.use(spies);
const expect = chai.expect;
//create app without credentials
let app = express();
app.use(express.urlencoded({ extended: false }));
app.set('view engine', 'ejs');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(route);
describe('Testing the POST /login route', () => {
let spy = chai.spy.on(request, 'post', (options, callback) => {
callback();
});
it('should make a request to backend server when form is filled, but with wrong credentials', (done) => {
supertest(app)
.post('/login')
.set('Accept', 'application/json')
.send({ username: 'test', password: 'test' })
.end(function(err, res) {
expect(spy).to.have.been.called.once;
done();
});
});
});

单元测试结果：

Testing the POST /login route
✓ should make a request to backend server when form is filled, but with wrong credentials (47ms)

1 passing (63ms)
----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |   92.31 |      100 |     100 |   92.31 |                   
index.js |   92.31 |      100 |     100 |   92.31 | 23                
----------|---------|----------|---------|---------|-------------------