Node.js中路由器下的Mock函数

Question

请考虑以下场景，但我无法解决。在路由器("/"(下调用了一个类。我想测试路由器("/"(调用并模拟myFunc结果。

class A {
myFunc = async () => {
await ...
return result
}
}

---

Controller file - C:
router.get("/", async (req, res) => {
var a = new A();
a.myFunc()
.then(result => {
res.json({"message": result});
}).catch(e => {
return []
})
});

---

C.test.js:
const request = require("supertest");
const app = require("../C");
jest.mock('A');
test("Test route /", async done => {
const myFuncMock = jest.fn().mockImplementation(() => [...]);
A.prototype.myFunc = myFuncMock;
await request(app)
.get("/")
.then(res => {
expect(res.status).toBe(200); // Not asserted
});
done()
});

我无法成功地模拟路由器下的功能结果。

Answer 1

这是集成测试解决方案：

app.js:

const express = require('express');
const { Router } = require('express');
const A = require('./a');
const app = express();
const router = Router();
router.get('/', async (req, res) => {
const a = new A();
a.myFunc()
.then((result) => {
res.json({ message: result });
})
.catch((e) => {
return [];
});
});
app.use(router);
module.exports = app;

a.js:

class A {
myFunc = async () => {
const result = await 'real data';
return result;
};
}
module.exports = A;

app.test.js:

const app = require('./app');
const request = require('supertest');
const A = require('./a');
jest.mock('./a', () => {
const mA = { myFunc: jest.fn() };
return jest.fn(() => mA);
});
describe('61505692', () => {
afterEach(() => {
jest.clearAllMocks();
});
it('should pass', () => {
const mA = new A();
mA.myFunc.mockResolvedValueOnce('fake result');
return request(app)
.get('/')
.then((res) => {
expect(res.status).toBe(200);
});
});
});

集成测试结果与覆盖率报告：

PASS  stackoverflow/61505692/app.test.js (11.834s)
61505692
✓ should pass (34ms)
----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s 
----------|---------|----------|---------|---------|-------------------
All files |   92.31 |      100 |      75 |   91.67 |                   
app.js   |   92.31 |      100 |      75 |   91.67 | 16                
----------|---------|----------|---------|---------|-------------------
Test Suites: 1 passed, 1 total
Tests:       1 passed, 1 total
Snapshots:   0 total
Time:        13.785s