protractor-cucumber auto screenshot failures

failure-hooks.js

let {defineSupportCode} = require('cucumber');

defineSupportCode(({After}) => {
  After(function(scenario, done) {
    let world = this;

    if (scenario.isFailed()) {
      world.takeAndSaveScreenshot().then(function(filename) {
        console.log(`Screenshot saved at ${filename}`); //eslint-disable-line no-console
        done();
      });
    } else {
      done();
    }
  });
});

world.js

let Q = require('q');
let fs = require('fs');
let path = require('path');
let {defineSupportCode} = require('cucumber');

defineSupportCode(({setWorldConstructor}) => {
  setWorldConstructor(World);
});

function World() {
  return {
    takeAndSaveScreenshot
  };
}

function takeAndSaveScreenshot() {
  let timestamp = new Date().getTime();

  return browser.waitForAngular()
    .then(getHtml)
    .then(saveHtml.bind(null, timestamp))
    .then(browser.takeScreenshot.bind(browser))
    .then(saveScreenshot.bind(null, timestamp));
}

function getHtml() {
  return browser.executeScript('return arguments[0].outerHTML;', element(by.css('html')));
}

function screenshotsDir() {
  let dir = path.resolve(__dirname, '..', '..', '..', 'build', 'screenshots');
  mkdir(dir);
  return dir;
}

function saveHtml(timestamp, html) {
  let fileName = path.join(screenshotsDir(), `${timestamp}.html`);
  return Q.nfcall(fs.writeFile, fileName, html);
}

function saveScreenshot(timestamp, stream) {
  let fileName = path.join(screenshotsDir(), `${timestamp}.png`);

  return Q.nfcall(fs.writeFile, fileName, new Buffer(stream, 'base64')).then(function() {
    return fileName;
  });
}

function mkdir(dir) {
  try {
    fs.mkdirSync(dir);
  } catch (e) {
    if (e.code !== 'EEXIST') {
      throw e;
    }
  }
}