<p>我正在努力通过我的代码库的端到端测试来实现良好的覆盖率,所以我也想测试 <code>.catch()</code> 代码。</p><p>
我的API使用node.js和mongoose。</p><p>
我使用chai和mocha进行测试。</p>
<p>我尝试了类似以下的代码:</p>
<p><em>文件 src/controllers/user.controller.js:</em></p>
<pre class="brush:php;toolbar:false;">const User = require("../models/user.model");
const getUser = async(req, res) => {
try {
const user = await User.findOne({name: req.name});
return res.status(200).json(user);
} catch (err) {
// 这是我想要测试的代码
console.error(`查找用户 ${req.name} 时出错:`, err);
return res.status(err.code).json({ message: err });
}
}</pre>
<p><em>文件 src/models/user.model.js:</em></p>
<pre class="brush:php;toolbar:false;">const mongoose = require("mongoose");
const UserSchema = mongoose.Schema({
name: {
type: String,
required: "Name is required",
},
});
module.exports = mongoose.model("User", UserSchema);</pre>
<p><em>文件 test/user.test.js:</em></p>
<pre class="brush:php;toolbar:false;">const chai = require("chai");
const chaiHttp = require("chai-http");
const spies = require("chai-spies");
const User = require("../src/models/user.model");
chai.use(chaiHttp);
chai.use(spies);
chai.should();
describe("应处理mongoose错误", function() {
describe("有问题的User.findOne方法", function() {
const _User_findOne_Backup = User.findOne;
beforeEach(function() {
// 这个函数应该重载真正的findOne函数,但它没有成功!
User.findOne = function() {
return Promise.reject("强制错误");
};
});
afterEach(function() { // 每个测试后恢复真正的函数
User.findOne = _User_findOne_Backup;
});
it("注册应该返回服务器错误", function() {
const spy = chai.spy();
return chai
.request(server)
.post("/api/getUser")
.send({name: "Alice"})
.then(spy)
.catch((err) => {
const res = err.response;
res.should.have.status(500);
})
.then(() => {
spy.should.not.have.been.called();
})
;
});
});
});</pre>
<p>问题是在我的测试中,伪造的 <code>User.findOne()</code> 方法从未被调用:原始的mongoose <code>findOne</code> 方法被调用成功,所以 <code>getUser</code> 方法从不抛出异常,导致我的测试失败...</p>
<p>可能我漏掉了一些明显的东西,但我真的找不到它... :-(</p><p>
如果需要更多的代码或上下文,请告诉我...</p>
<p><strong>更新:</strong>
根据 @Bergi 的建议,我添加了关于我的(简化的)模型和所需模块的完整信息...</p>
对我来说很好用。
例如:
user.model.js:const mongoose = require("mongoose"); const UserSchema = mongoose.Schema({ name: { type: String, required: "Name is required", }, }); module.exports = mongoose.model("User", UserSchema);user.controller.js:const User = require("./user.model"); const getUser = async (req, res) => { try { const user = await User.findOne({ name: req.body.name }); return res.status(200).json(user); } catch (err) { console.error(`Error finding user ${req.body.name}:`, err); return res.status(500).json({ message: err }); } } module.exports = { getUser }server.js:const express = require('express'); const userController = require('./user.controller'); const app = express(); app.use(express.json()) app.post('/api/getUser', userController.getUser) module.exports = app;user.test.js:const chai = require("chai"); const chaiHttp = require("chai-http"); const User = require("./user.model"); const server = require('./server'); chai.use(chaiHttp); chai.should(); describe("should handle mongoose errors", function () { describe("faulty User.findOne method", function () { const _User_findOne_Backup = User.findOne; beforeEach(function () { User.findOne = function () { return Promise.reject("forced error"); }; }); afterEach(function () { User.findOne = _User_findOne_Backup; }); it("signup should respond with a server error", function () { return chai .request(server) .post("/api/getUser") .send({ name: "Alice" }) .catch((err) => { const res = err.response; res.should.have.status(500); }) ; }); }); });测试结果:
should handle mongoose errors faulty User.findOne method Error finding user Alice: forced error ✓ signup should respond with a server error 1 passing (21ms) --------------------|----------|----------|----------|----------|-------------------| File | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s | --------------------|----------|----------|----------|----------|-------------------| All files | 89.19 | 100 | 88.89 | 88.57 | | server.js | 100 | 100 | 100 | 100 | | user.controller.js | 80 | 100 | 100 | 75 | 6,7 | user.model.js | 100 | 100 | 100 | 100 | | user.test.js | 88.89 | 100 | 85.71 | 88.89 | 26,27 | --------------------|----------|----------|----------|----------|-------------------|软件包版本: