karma.conf.js

// Karma configuration
const webpack = require('./webpack.config');
const testEntrypoint = './test/index.ts';

module.exports = function (config) {
    config.set({
        // this key is used by karma-webpack, see preprocessors below
        webpack,

        // the default mime type for ts files is video/mp2t, which Chrome won't execute, so force correct mime type
        mime: {
            "text/x-typescript": ["ts", "tsx"],
        },

        // base path that will be used to resolve all patterns (eg. files, exclude)
        basePath: '',


        // frameworks to use
        // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
        frameworks: ['mocha'],


        // list of files / patterns to load in the browser
        files: [
            testEntrypoint
        ],


        // list of files to exclude
        exclude: [
        ],


        // preprocess matching files before serving them to the browser
        // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
        preprocessors: {
            [testEntrypoint]: ['webpack']
        },


        // test results reporter to use
        // possible values: 'dots', 'progress'
        // available reporters: https://npmjs.org/browse/keyword/karma-reporter
        reporters: ['spec'],


        // web server port
        port: 9876,


        // enable / disable colors in the output (reporters and logs)
        colors: true,


        // level of logging
        // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
        logLevel: config.LOG_INFO,


        // enable / disable watching file and executing tests whenever any file changes
        autoWatch: true,


        // start these browsers
        // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
        browsers: ['ChromeHeadlessNoSandbox'],

        customLaunchers: {
            ChromeHeadlessNoSandbox: {
                base: 'ChromeHeadless',
                flags: ['--no-sandbox']
            }
        },

        // Continuous Integration mode
        // if true, Karma captures browsers, runs the tests and exits
        singleRun: false,

        // Concurrency level
        // how many browser should be started simultaneous
        concurrency: Infinity,

        // https://docs.travis-ci.com/user/gui-and-headless-browsers/#Karma-and-Firefox-inactivity-timeouts
        browserNoActivityTimeout: 30000
    })
}