Launching an Express Server for jest-puppeteer Tests on a React Application

Other Questions Puppeteer
1

I want to conditionally start my Express server for testing, launching it solely for GET React page validations. Updated server and test snippet examples are provided below:

// server setup example
const router = require('express')();
if (process.env.NODE_ENV === 'test') {
  module.exports = { router };
} else {
  router.listen(3000);
}

describe('GET endpoint test', () => {
  it('delivers the React page', async () => {
    await pageInstance.goto('http://127.0.0.1:3000/');
    await expect(pageInstance).toContainText(/sample/);
  });
});
2

I have faced similar challenges when trying to conditionally start an Express server during tests. In my experience, ensuring that the Express instance only launches when not in a testing environment helped prevent port conflicts, especially when tests run concurrently. However, one improvement I made was to add error-handling so that any startup issues during the test environment are caught early. Additionally, using a more controlled approach where the server starts in a separate process allowed me to mitigate race conditions in setup and teardown routines. This approach enhanced the stability of the testing workflow.

3

I have encountered similar issues when conditionally starting an Express server for testing. I resolved it by isolating the server startup logic in a dedicated module that manages initialization based on the environment variable. I made sure that any errors during server startup were logged and propagated correctly, preventing the test runner from silently failing. This approach avoids potential conflicts caused by asynchronous startup and race conditions. In my experience, separating the server logic from the test setup not only improves clarity but also enhances the reliability and maintainability of the testing process.