karma.conf.js

var path = require("path");
var webpack = require("webpack");

module.exports = function (config) {
  var customLaunchers = {
    BS_Chrome: {
      name: "Chrome",
      base: "BrowserStack",
      os: "Windows",
      os_version: "10",
      browser: "Chrome",
      browser_version: "73.0",
    },
    // BS_ChromeAndroid: {
    //   base: 'BrowserStack',
    //   device: 'Samsung Galaxy S8',
    //   os_version: '7.0',
    //   real_mobile: true
    // },
    BS_Firefox: {
      name: "Firefox",
      base: "BrowserStack",
      os: "Windows",
      os_version: "10",
      browser: "Firefox",
      browser_version: "67.0",
    },
    BS_Edge: {
      name: "Edge",
      base: "BrowserStack",
      os: "Windows",
      os_version: "10",
      browser: "Edge",
      browser_version: "17.0",
    },
    BS_IE11: {
      name: "IE 11",
      base: "BrowserStack",
      os: "Windows",
      os_version: "10",
      browser: "IE",
      browser_version: "11.0",
    },
    // Safari throws an error if you use replaceState more
    // than 100 times in 30 seconds :/
    // BS_Safari: {
    //   base: 'BrowserStack',
    //   os: 'OS X',
    //   os_version: 'Mojave',
    //   browser: 'Safari',
    //   browser_version: '12.1'
    // }
    // BS_iPhoneX: {
    //   base: 'BrowserStack',
    //   device: 'iPhone X',
    //   os_version: '11',
    //   real_mobile: true
    // },
    // BS_iPhoneXS: {
    //   base: 'BrowserStack',
    //   device: 'iPhone XS',
    //   os_version: '12',
    //   real_mobile: true
    // },
  };

  config.set({
    singleRun: true,
    customLaunchers: customLaunchers,
    browsers: ["Chrome" /*, 'Firefox'*/],
    frameworks: ["mocha" /*, 'webpack' */],
    reporters: ["mocha"],
    files: ["tests.webpack.js"],
    preprocessors: {
      "tests.webpack.js": ["webpack", "sourcemap"],
    },
    webpack: {
      // TODO: Webpack 4+
      // mode: 'none',
      devtool: "inline-source-map",
      resolve: {
        modules: [path.resolve(__dirname, "../"), "node_modules"],
        alias: {
          history: path.resolve(__dirname, "../build/history"),
        },
      },
      module: {
        rules: [
          {
            test: /__tests__\/.*\.js$/,
            exclude: /node_modules/,
            use: {
              loader: "babel-loader",
              options: {
                presets: ["@babel/preset-env"],
              },
            },
          },
        ],
      },
      plugins: [
        new webpack.DefinePlugin({
          "process.env.NODE_ENV": JSON.stringify("test"),
        }),
      ],
    },
    webpackServer: {
      noInfo: true,
    },
  });

  if (process.env.TRAVIS || process.env.USE_CLOUD) {
    config.browsers = Object.keys(customLaunchers);
    config.reporters = ["dots"];
    config.concurrency = 2;
    config.browserDisconnectTimeout = 10000;
    config.browserDisconnectTolerance = 3;

    if (process.env.TRAVIS) {
      config.browserStack = {
        project: "history",
        build: process.env.TRAVIS_BRANCH,
      };
    } else {
      config.browserStack = {
        project: "history",
      };
    }
  }
};