pre-commit hook

gistfile1.txt

#!/usr/bin/env ruby
REQUIRED_GEMS = %w(rubocop)

REQUIRED_GEMS.each do |gem_name|
  begin
    require gem_name
  rescue LoadError => e
    puts "=" * 50
    puts "Please ensure that '#{gem_name}' is installed on your system e.g. `gem install #{gem_name}`"
    puts "=" * 50
    raise
  end
end

class GitStatus
  ADDED_OR_MODIFIED = /A|AM|^M/.freeze

  def changed_files(file_extension_filters: [])
    if file_extension_filters.any?
      new_or_modified_filenames.select do |filename|
        file_extension_filters.include?(File.extname(filename).delete('.'))
      end
    else
      new_or_modified_filenames
    end
  end

  private

  def git_status
    @git_status ||= `git status --porcelain`.split(/\n/)
  end

  def new_or_modified_filenames
    git_status.select do |filename_with_status|
      filename_with_status =~ ADDED_OR_MODIFIED
    end.map do |filename_with_status|
      filename_with_status.split(' ')[1]
    end
  end
end

class Linter
  def initialize(filename_list)
    @filename_list = filename_list
  end

  def lint!
    puts "======== Linting with #{linter_name} ========"

    exit_status = system("#{lint_executable} #{filenames_as_single_line}")

    puts "\n"

    exit_status
  end

  private

  attr_reader :filename_list

  def filenames_as_single_line
    filename_list.join(' ')
  end
end

class Linter::Rubocop < Linter
  def self.file_extensions
    %w(rb)
  end

  def lint_executable
    'bundle exec rubocop --force-exclusion'
  end

  def linter_name
    'rubocop'
  end
end

class Linter::SASSLint < Linter
  def self.file_extensions
     %w(scss)
  end

  def lint_executable
    'yarn run sass-lint'
  end

  def linter_name
    'sass-lint'
  end
end

class Linter::JSHint < Linter
  def self.file_extensions
    %w(js js.erb)
  end

  def lint_executable
    'yarn run jshint-single'
  end

  def linter_name
    'jshint'
  end

  private

  def filename_list
    @filename_list.select { |filename| filename =~ %r{app/assets/javascripts/} }
  end
end

class Linter::JSCS < Linter
  def self.file_extensions
    %w(js js.erb)
  end

  def lint_executable
    'yarn run jscs-single'
  end

  def linter_name
    'jscs'
  end
end

class Linter::HAMLLint < Linter
  def self.file_extensions
     %w(haml)
  end

  def lint_executable
    'bundle exec haml-lint'
  end

  def linter_name
    'haml-lint'
  end
end

class Linter::ESLint < Linter
  def self.file_extensions
    %w(js jsx)
  end

  def lint_executable
    'yarn run eslint-single -- --quiet'
  end

  def linter_name
    'eslint'
  end

  private

  def filename_list
    files_that_use_es6
  end

  def files_that_use_es6
    @filename_list.select { |filename| filename =~ %r{app/javascript/} }
  end
end

class Linter::Locale < Linter
  def self.file_extensions
    %w(yml)
  end

  def lint_executable
    'bundle exec rake lint:locale'
  end

  def linter_name
    'locale'
  end

  private

  def filename_list
    @filename_list.select { |filename| filename =~ %r{config/locales/en.yml} }
  end
end

linters = [
  Linter::Rubocop,
  Linter::JSHint,
  Linter::JSCS,
  Linter::ESLint,
  Linter::SASSLint,
  Linter::HAMLLint,
  Linter::Locale
]

git_status = GitStatus.new

linter_exit_statuses = []

linters.each do |linter_class|
  changed_filename_list = git_status.changed_files(file_extension_filters: linter_class.file_extensions)

  if changed_filename_list.any?
    linter_exit_statuses << linter_class.new(changed_filename_list).lint!
  end
end

if linter_exit_statuses.all? { |status| status == true }
  exit 0
else
  exit 1
end