karma.conf.js

const path = require('path');
const webpackConfig = require('./webpack.config.dev.js');

module.exports = function (config) {
  config.set({

    frameworks: ['jasmine'],
    files: [
      'test/**/*.js',
    ],
    port: 9876, // karma web server port
    colors: true,
    logLevel: config.LOG_INFO,
    browsers: ['ChromeHeadlessNoSandbox'],
    customLaunchers: {
      ChromeHeadlessNoSandbox: {
        base: 'Chrome',
        flags: [
          '--no-sandbox',
          '--disable-setuid-sandbox',
          '--headless',
          '--disable-gpu',
          '--remote-debugging-port=9222',
        ]
      }
    },
    autoWatch: true,
    singleRun: false, // Karma captures browsers, runs the tests and exits
    concurrency: Infinity,

    preprocessors: {
      'test/**/*.js': ['webpack', 'sourcemap'],
    },

    reporters: ['progress', 'coverage-istanbul'],


    // anything named karma-* is normally auto included so you probably dont need this
    plugins: ['karma-coverage-istanbul-reporter', 'karma-jasmine', 'karma-chrome-launcher', 'karma-sourcemap-loader', 'karma-webpack'],

    webpack: webpackConfig,

    webpackMiddleware: {
      // webpack-dev-middleware configuration
      // i.e.
      noInfo: true,
      // and use stats to turn off verbose output
      stats: {
        // options i.e.
        chunks: false
      }
    },

    // any of these options are valid: https://github.com/istanbuljs/istanbuljs/blob/aae256fb8b9a3d19414dcf069c592e88712c32c6/packages/istanbul-api/lib/config.js#L33-L39
    coverageIstanbulReporter: {
      // reports can be any that are listed here: https://github.com/istanbuljs/istanbuljs/tree/aae256fb8b9a3d19414dcf069c592e88712c32c6/packages/istanbul-reports/lib
      reports: ['html', 'lcovonly', 'text-summary'],

      // base output directory. If you include %browser% in the path it will be replaced with the karma browser name
      dir: path.join(__dirname, 'coverage'),

      // Combines coverage information from multiple browsers into one report rather than outputting a report
      // for each browser.
      combineBrowserReports: true,

      // if using webpack and pre-loaders, work around webpack breaking the source path
      fixWebpackSourcePaths: true,

      // Omit files with no statements, no functions and no branches from the report
      skipFilesWithNoCoverage: true,

      // Most reporters accept additional config options. You can pass these through the `report-config` option
      'report-config': {
        // all options available at: https://github.com/istanbuljs/istanbuljs/blob/aae256fb8b9a3d19414dcf069c592e88712c32c6/packages/istanbul-reports/lib/html/index.js#L135-L137
        html: {
          // outputs the report in ./coverage/html
          subdir: 'html'
        }
      },

      // enforce percentage thresholds
      // anything under these percentages will cause karma to fail with an exit code of 1 if not running in watch mode
      thresholds: {
        emitWarning: true, // set to `true` to not fail the test command when thresholds are not met
        // thresholds for all files
        global: {
          statements: 65,
          lines: 65,
          branches: 65,
          functions: 65
        },
        // thresholds per file
        each: {
          statements: 65,
          lines: 65,
          branches: 65,
          functions: 65
        }
      },

      verbose: false // output config used by istanbul for debugging
    }
  });
};