在测试中添加应用程序级表达中间件

Question

演示：https://codesandbox.io/s/mocha-chai-http-tests-o31ov我尝试在测试阶段像这样添加应用程序级中间件

it("GET/ Get custom response", function(done) {
    app.use("/custom", (req, res, next) => {
      res.status(200).send({
        customMessage: "custom",
        customData: {
          version: "v1"
        }
      });
    });

    chai
      .request(app)
      .get("/custom")
      .end((err, res) => {
        console.log("CUSTOM", res.body);
        res.should.have.status(200);
        res.body.should.be.a("object");
        res.body.should.have.property("customMessage");
        res.body.should.have.property("customData");
        done();
      });
  });

但是测试没有使用它，它从根本上属于404中间件。如何在测试中使用自定义路由？

Answer 1

中间件的加载顺序很重要：首先加载的中间件功能也将首先执行。

[尝试访问/custom路由的原因404是在404错误处理程序中间件之后加载此路由。我们需要在404错误处理程序中间件之前保持/custom路由负载。这是一个解决方案：

app.js：

const createError = require('http-errors');
const express = require('express');

function createApp(customRoute) {
  const app = express();

  app.use(express.json());
  app.use(express.urlencoded({ extended: false }));
  app.use('/api', function(req, res) {
    res.status(200).send({
      message: 'API',
      data: {
        version: 'v1',
      },
    });
  });
  if (customRoute) {
    app.use(customRoute.route, customRoute.controller);
  }

  // catch 404 and forward to error handler
  app.use(function(req, res, next) {
    next(createError(404));
  });

  // error handler
  app.use(function(err, req, res, next) {
    res.status(err.status).send({
      status: err.status,
      error: err,
    });
  });

  return app;
}

module.exports = createApp;

app.test.js：

const chai = require('chai');
const chaiHttp = require('chai-http');
const createApp = require('./app');

chai.use(chaiHttp);
chai.should();

describe('API test', function() {
  it('GET/ Get root response', function(done) {
    const app = createApp();
    chai
      .request(app)
      .get('/api')
      .end((err, res) => {
        console.log('NORMAL', res.body);
        res.should.have.status(200);
        res.body.should.be.a('object');
        res.body.should.have.property('message');
        res.body.should.have.property('data');
        done();
      });
  });

  it('GET/ Get custom response', function(done) {
    const customRoute = {
      route: '/custom',
      controller: (req, res, next) => {
        res.status(200).send({
          customMessage: 'custom',
          customData: {
            version: 'v1',
          },
        });
      },
    };
    const app = createApp(customRoute);

    chai
      .request(app)
      .get('/custom')
      .end((err, res) => {
        console.log('CUSTOM', res.body);
        res.should.have.status(200);
        res.body.should.be.a('object');
        res.body.should.have.property('customMessage');
        res.body.should.have.property('customData');
        done();
      });
  });
});

单元测试结果：

  API test
NORMAL { message: 'API', data: { version: 'v1' } }
    ✓ GET/ Get root response (44ms)
CUSTOM { customMessage: 'custom', customData: { version: 'v1' } }
    ✓ GET/ Get custom response


  2 passing (62ms)