Run Angular Unit Test Cases Without Browser | Karma | Jasmine

There are two way to configure the Angular unit test cases to run without the browser.

From command line

While running the unit test cases you can specify the browsers as ChromeHeadless,

ng test --browsers ChromeHeadless

From karma.conf.json

Open you karma.conf.json and add the following:

browsers: ['ChromeHeadless']

Here is the how the modified karma.conf.json file looks:

// Karma configuration file, see link for more information
// https://karma-runner.github.io/1.0/config/configuration-file.html

module.exports = function (config) {
  config.set({
    basePath: '',
    frameworks: ['jasmine', '@angular-devkit/build-angular'],
    plugins: [
      require('karma-jasmine'),
      require('karma-chrome-launcher'),
      require('karma-jasmine-html-reporter'),
      require('karma-coverage-istanbul-reporter'),
      require('@angular-devkit/build-angular/plugins/karma')
    ],
    client: {
      clearContext: false // leave Jasmine Spec Runner output visible in browser
    },
    coverageIstanbulReporter: {
      dir: require('path').join(__dirname, './coverage/angu-unit-test'),
      reports: ['html', 'lcovonly', 'text-summary'],
      fixWebpackSourcePaths: true
    },
    reporters: ['progress', 'kjhtml'],
    port: 9876,
    colors: true,
    logLevel: config.LOG_INFO,
    autoWatch: true,
    browsers: ['ChromeHeadless'],
    singleRun: false,
    restartOnFileChange: true
  });
};