text: /* eslint-env node */
  const { createDefaultConfig } = require('@open-wc/testing-karma');
  const merge = require('deepmerge');
  
  const defaultPattern = '+(components|helpers|mixins|templates)/**/*.test.js';
  
  module.exports = config => {
  	config.set(
  		merge(createDefaultConfig(config), {
  			files: [
  				// runs all files ending with .test in the test folder,
  				// can be overwritten by passing a --grep flag. examples:
  				//
  				// npm run test -- --grep test/foo/bar.test.js
  				// npm run test -- --grep test/bar/*
  				{ pattern: config.grep ? config.grep : defaultPattern, type: 'module' },
  			],
  			// see the karma-esm docs for all options
  			esm: {
  				// if you are using 'bare module imports' you will need this option
  				nodeResolve: true,
  			},
  		}),
  	);
  	return config;
  };
  