Unit Testing with Angular 5 in a Headless Browser Environment

Other Questions Headless Browser
1

I am utilizing Karma and Jasmine for unit testing in my Angular 5 application. The tests execute perfectly on my local machine, but they encounter issues on my Ubuntu server when run with HeadlessChrome. Here’s a snippet of the log showing the problem:

05 03 2018 07:43:02.132:INFO [HeadlessChrome 64.0.3282 (Ubuntu 0.0.0)]: Connected on socket 9NdPfrccf8iYNlPrAAAA with id 56814881
05 03 2018 07:45:21.364:WARN [HeadlessChrome 64.0.3282 (Ubuntu 0.0.0)]: Disconnected (1 times)
HeadlessChrome 64.0.3282 (Ubuntu 0.0.0) ERROR
  Disconnectedundefined

Interestingly, the tests function correctly when using Headless Firefox. I would appreciate any assistance in resolving this issue!

2

Hey, it looks like a common issue with Headless Chrome on Ubuntu. Try increasing the browserNoActivityTimeout in your karma.conf.js to avoid disconnects:

module.exports = function(config) {
  config.set({
    ...
    browserNoActivityTimeout: 60000,
  });
};

If that doesn't help, ensure that the server has sufficient resources since Headless Chrome requires more than Firefox. Also, double-check your Chrome dependencies are up to date.

3

An alternative approach you might consider is ensuring that the proper environment dependencies are configured for Headless Chrome on your Ubuntu server. Here's a checklist of potential solutions you might explore:

  • Check for Missing Dependencies: Ensure that all necessary dependencies for Headless Chrome are installed on the server. Sometimes certain libraries required by Chrome might be missing. You can install them using:
sudo apt-get install -y libnss3 libxss1 libasound2 fonts-liberation libappindicator3-1
  • Update Chromium Package: Make sure that you are using the latest version of Chromium and its associated packages. Older versions can sometimes behave unpredictably, especially in headless mode.
  • Run Tests in Debug Mode: Sometimes, running your tests in debug mode provides more verbose output, which can help you identify when and where the disconnect is occurring. You can enable debugging in your Karma configuration:
module.exports = function(config) {
  config.set({
    ...
    browsers: ['ChromeDebugging'],
    customLaunchers: {
      ChromeDebugging: {
        base: 'Chrome',
        flags: [ '--remote-debugging-port=9222' ],
      },
    },
  });
};
  • Resource Evaluation: Evaluate the available resources on your server, such as CPU and memory. Sometimes browser processes are terminated prematurely if they exceed the resource limits. Adjusting your resource allocation might resolve the disconnect.
  • Network Issues: Since you are using a server environment, network interruptions might also be contributing to the disconnects. Ensure that network stability is not a factor.

These steps might help you address the issue you're facing with Headless Chrome. If you continue to experience the problem, consider providing more detailed logs, which might highlight the underlying cause more explicitly.

4

If you're still experiencing issues with Headless Chrome on Ubuntu, consider streamlining your setup further to ensure optimal compatibility and resource management:

1. Optimize Karma Configuration:

Sometimes, tweaking the Karma configuration can help stabilize the connection. Ensure you're using the recommended settings for Headless Chrome.

module.exports = function(config) {
  config.set({
    ...
    browsers: ['ChromeHeadless'],
    customLaunchers: {
      ChromeHeadless: {
        base: 'Chrome',
        flags: ['--no-sandbox', '--disable-gpu'] // Add these flags for better headless stability
      },
    },
  });
};

2. Review System Logs:

Examine the system logs for any error messages or warnings related to Chrome processes. This can often reveal conflicts or unreported issues.

3. Increase Heap Size:

If your tests involve complex operations or large datasets, Chrome may require more memory. Increase the max_old_space_size:

CHROME_BIN=/usr/bin/google-chrome node --max_old_space_size=4096 ./node_modules/karma/bin/karma start

4. Consider Alternative Testing Tools:

If the issue persists, you might want to explore using alternative test runners like Cypress which offer more resilient handling of headless environments.

These approaches should help you achieve a more stable test execution on your Ubuntu server.

5

Hey there! If your tests still misbehave with Headless Chrome on Ubuntu, consider adjusting how Chrome is invoked. This could stabilize its execution:

1. Use Puppeteer:

Puppeteer can launch Chrome browsers programmatically with a few tweaks. It helps manage the execution flow, especially in headless environments:

const puppeteer = require('puppeteer');
(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  await page.goto('http://localhost:9876', {
    waitUntil: 'networkidle2',
  });
  await browser.close();
})();

2. Configure Karma with Puppeteer:

Enable Puppeteer to run your tests:

module.exports = function(config) {
  config.set({
    ...
    browsers: ['ChromeHeadlessPuppeteer'],
    customLaunchers: {
      ChromeHeadlessPuppeteer: {
        base: 'ChromeHeadless',
        flags: ['--no-sandbox', '--disable-setuid-sandbox'],
      }
    },
  });
};

These steps might enhance the stability of your test suite in a headless setup.