Wercker setup for Rails 5.x with Webpack (tests + system tests + rubocop + eslint + stylelint)

wercker.yml

box: ruby:2.5.0

# http://devcenter.wercker.com/docs/services/index.html
services:
    - redis
    - id: postgres
      env:
       POSTGRES_PASSWORD: ourlittlesecret
       POSTGRES_USER: testuser
build:
    # http://devcenter.wercker.com/docs/steps/index.html
    steps:
        - rails-database-yml
        - script:
            name: nokogiri tricks
            code: bundle config build.nokogiri --use-system-libraries
        - bundle-install:
            without: development
        - bigtruedata/install-node@2.1.1:
            version: 9.7.1
        - akupila/yarn@0.2.0
        - script:
            name: yarn install
            code: yarn install
        - script:
            name: install chrome headless
            code: |
              apt-get update -y
              apt-get install -y ca-certificates apt-transport-https ttf-wqy-zenhei fonts-unfonts-core
              wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | apt-key add -
              echo "deb https://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google-chrome.list
              apt-get update -y
              apt-get install -y google-chrome-stable
        - script:
            name: set chrome headless
            code: |
              export CHROME_BIN=/usr/bin/google-chrome-stable
        - script:
            name: load db schema
            code: RAILS_ENV=test bundle exec rake db:schema:load
        - script:
            name: prepare tests
            code: RAILS_ENV=test bundle exec rake db:test:prepare
        - script:
            name: test
            code: RAILS_ENV=test bundle exec rake test
        - script:
            name: test system
            code: RAILS_ENV=test bundle exec rake test:system
        - script:
            name: rubocop
            code: bundle exec rubocop
        - script:
            name: eslint
            code: ./node_modules/.bin/eslint frontend/ --ext js,jsx
        - script:
            name: stylelint
            code: ./node_modules/.bin/stylelint "app/assets/stylesheets/**/*.scss frontend/**/*.scss"

group :test do
  # wercker requirements
  gem 'execjs'
  gem 'therubyracer'
end