I want to run tests on my node express server however this application is starting the server like this:

createServer()
.then(server => {
    server.listen(PORT);
    Log.info(`Server started on http://localhost:${PORT}`);
})
.catch(err => {
    Log.error("Startup failure.", { error: err });
    process.exit(1);
});

and I know the chai.request() needs to have a parameter that is pointing toward the server app, how can I export/import this createServer() function and pass it in the request method of the chai object?

CodePudding user response：

You can use require.main to distinguish between your files being run directly by Node or imported as modules.

When a file is run directly from Node.js, require.main is set to its module. That means that it is possible to determine whether a file has been run directly by testing require.main === module.

E.g.

server.js:

const express = require('express');

const PORT = 3000;
async function createServer() {
  const app = express();
  app.get('/', (req, res) => {
    res.send('hello world');
  });
  return app;
}

if (require.main === module) {
  createServer()
    .then((server) => {
      server.listen(PORT);
      console.info(`Server started on http://localhost:${PORT}`);
    })
    .catch((err) => {
      console.error('Startup failure.', { error: err });
      process.exit(1);
    });
}

module.exports = { createServer };

When you import the createServer from the server.js file, the if statement block will not execute. Because you want to create the server instance in the test case.

server.test.js:

const { createServer } = require('./server');
const chai = require('chai');
const chaiHTTP = require('chai-http');
const { expect } = require('chai');
chai.use(chaiHTTP);

describe('70284767', () => {
  it('should pass', async () => {
    const server = await createServer();
    chai
      .request(server)
      .get('/')
      .end((err, res) => {
        expect(err).to.be.null;
        expect(res.text).to.be.equal('hello world');
      });
  });
});