code: function getConfig(fullConfig) {
    // ensure we can manipulate config settings
    const config = (fullConfig.parallelOptions =
      fullConfig.parallelOptions || {});
    config.shardIndexMap = {};
    config.nextShardIndex = {};
    config.browserIdAlias = {};
    config.shardStrategy = config.shardStrategy || 'round-robin';
    config.customShardStrategy =
      config.customShardStrategy ||
      function() {
        throw new Error(
          'Should specify a "customShardStrategy" function when using shardStrategy: "custom"'
        );
      };
    config.aggregatedReporterTest =
      'aggregatedReporterTest' in config
        ? config.aggregatedReporterTest
        : /coverage|istanbul|junit/i;
    config.executors = Math.max(
      1,
      config.executors || require('os').cpus().length - 1
    );
    return config;
  }
docs: jshint node: true