karma.conf.js

"use strict";

process.env.CHROME_BIN = require("puppeteer").executablePath();

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

        // 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: [
            "node_modules/mocha/mocha.js",
            "node_modules/chai/chai.js",
            "node_modules/sinon/pkg/sinon.js",
            "build/eslint.js",
            "tests/lib/linter.js"
        ],


        // 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: {
            "tests/lib/linter.js": ["babel"]
        },
        babelPreprocessor: {
            options: {
                presets: ["@babel/preset-env"]
            }
        },


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

        mochaReporter: {
            output: "minimal"
        },

        // 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: false,


        // start these browsers
        // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
        browsers: ["HeadlessChrome"],
        customLaunchers: {
          HeadlessChrome: {
            base: 'ChromeHeadless',
            flags: [ '--no-sandbox', ],
             },
            },

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

        // Concurrency level
        // how many browser should be started simultaneous
        concurrency: Infinity
    });
};