在开始 mocha 测试之前确保 express 应用程序是运行

Question

我使用 express 和 node.js 为 couchbase 数据库构建了一个 API。我的问题是，当我运行我的一些测试失败时，因为服务器没有完全运行ning。我在这里 https://mrvautin.com/ensure-express-app-started-before-tests 找到了关于如何解决这个问题的解决方案。文章指出，为了解决这个问题，您必须像这样在您的服务器文件中添加一个事件发射器

app.listen(app_port, app_host, function () {
    console.log('App has started');
    app.emit("appStarted");
});

然后在你的测试文件中添加这个

before(function (done) {
    app.on("appStarted", function(){
        done();
    });
});

我试过了，这是我的实现

服务器文件

app.listen(config['server']['port'], function(){
    app.emit("appStarted");
    logger.info("Listening")
})

测试文件

before(function(done){
    app.on("appStarted", function(){
        done();
    })
});

我不断收到以下错误

  1) "before all" hook in "{root}":
     Error: Timeout of 2000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves.
      at listOnTimeout (internal/timers.js:549:17)
      at processTimers (internal/timers.js:492:7)

这篇文章来自 2016 年，所以我在想可能语法已被弃用。我想知道是否有人可以帮我指明正确的方向？

Answer 1

您可以添加以下条件，更多信息见"Accessing the main module".

if (require.main === module) {
     // this module was run directly from the command line as in node xxx.js
} else {
     // this module was not run directly from the command line and probably loaded by something else
}

例如

index.ts:

import express from 'express';

const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.sendStatus(200);
});

if (require.main === module) {
  app.listen(port, () => {
    console.log('App has started');
  });
}

export { app, port };

index.test.ts:

import { app, port } from './';
import http from 'http';
import request from 'supertest';

describe('63822664', () => {
  let server: http.Server;
  before((done) => {
    server = app.listen(port, () => {
      console.log('App has started');
      done();
    });
  });
  after((done) => {
    server.close(done);
    console.log('App has closed');
  });
  it('should pass', () => {
    return request(server)
      .get('/')
      .expect(200);
  });
});

集成测试结果：

(node:22869) ExperimentalWarning: The fs.promises API is experimental
  63822664
App has started
    ✓ should pass
App has closed


  1 passing (26ms)

在开始 mocha 测试之前确保 express 应用程序是运行

Ensure express app is running before starting mocha tests

mocha.js

node.js

express

couchbase

supertest

在开始 mocha 测试之前确保 express 应用程序是 运行

Ensure express app is running before starting mocha tests

mocha.js

node.js

express

couchbase

supertest

在开始 mocha 测试之前确保 express 应用程序是运行