Error:

I'm using PhantomJS to run tests.

and get the following error:

Error: : fetch() method does not exist

Here is the karma.config.js file:

var webpackConfig = require('./webpack.config.js');

    module.exports = config => {
      config.set({
        basePath: '',
        frameworks: ['jasmine'],
        files: ['node_modules/babel-polyfill/dist/polyfill.js','./src/components/**/*.spec.ts'],
        preprocessors: {
          './src/components/**/*.spec.ts': ['webpack']
        },
        mime: {
          'text/x-typescript': ['ts', 'tsx']
        },
        webpack: webpackConfig,
        reporters: ['progress'],
        port: 9876,
        colors: true,
        logLevel: config.LOG_INFO,
        autoWatch: true,
        browsers: ['PhantomJS'],
        singleRun: false,
        webpackMiddleware: {
          noInfo: true
        },
        concurrency: Infinity
      });
    };