BrowserScreencast module for RSpec to capture screenscast using Ferrum screencast functionality in configure screenshots_dir.

browser_screencast.rb

# frozen_string_literal: true

module BrowserScreencast
  # Save screencast images from Ferrum

  def display_image(html:, screenshot_output:)
    message = super

    [
      "[Screencast]: #{screencast_dir}",
      message
    ].join("\n")
  end

  def ferrum_page
    page.driver.browser.page
  end

  def screencast_dir
    Rails.root.join(screenshots_dir, 'screencast').relative_path_from(Rails.root).to_s.tap do |dir|
      FileUtils.mkpath(dir)
    end
  end

  def start_screencast
    ferrum_page.start_screencast(format: :jpeg, quality: 75) do |data, metadata|
      timestamp = (metadata['timestamp'] * 1000).to_i
      File.binwrite(File.join(screencast_dir, "image_#{timestamp}.jpg"), Base64.decode64(data))
    end
  end

  delegate :stop_screencast, to: :ferrum_page
end

RSpec.configure do |config|
  config.include BrowserScreencast, type: :system

  config.before(:each, type: :system) do
    start_screencast
  end

  config.after(:each, type: :system) do
    stop_screencast

    # remove screencast if test passed
    FileUtils.rm_rf(screencast_dir) if passed?
  end
end