protractor-sharded.conf.js

const SHARD_COUNT = exports.SHARD_COUNT = +(process.env.PROTRACTOR_SHARD_COUNT || 4);

const _ = require('lodash');
const glob = require('glob');
const fs = require('fs');

exports.config = _.tap(_.clone(require('./protractor.conf.js').config), function (config) {
  config.getMultiCapabilities = function () {
    const shards = getShardedScenarios(getAllScenarios(config.capabilities.specs));

    return _.map(shards, function (files, i) {
      const shardNumber = ++i;

      return {
        browserName: process.env.PROTRACTOR_BROWSER || 'chrome',
        specs: files,
        cucumberOpts: _.tap(_.clone(config.cucumberOpts), function (options) {
          options.format = _.map(options.format, function (format) {
            return format.replace(/\.json/, `-${shardNumber}.json`);
          });
        })
      };
    });
  };

  function getAllScenarios (specs) {
    return _.flatten(_.map(glob.sync(specs), function (filename) {
      return _.reduce(fs.readFileSync(filename, {encoding: 'utf8'}).split('\n'), function (memo, line, i) {
        if (line.match(/^ *Scenario:/)) memo.push(`${filename}:${i + 1}`);
        return memo;
      }, []);
    }));
  }

  function getShardedScenarios (allScenarios) {
    const scenariosPerShard = Math.ceil(allScenarios.length / SHARD_COUNT);

    return _.reduce(allScenarios, function (memo, scenario) {
      let lastShard = _.last(memo);

      if (lastShard.length > scenariosPerShard) {
        lastShard = [];
        memo.push(lastShard);
      }

      lastShard.push(scenario);
      return memo;
    }, [[]]);
  }
});

protractor.conf.js

exports.config = {
  framework: 'custom',
  frameworkPath: 'node_modules/protractor-cucumber-framework',

  cucumberOpts: {
    format: ['json:./build/test-results/protractor.json', 'pretty'],
    require: ['features/step_definitions/**/*.js', 'features/support/**/*.js'],
    strict: true
  },

  capabilities: {
    browserName: process.env.PROTRACTOR_BROWSER || 'chrome',
    specs: 'features/**/*.feature'
  }
};