empty_hook.rb

# frozen_string_literal: true

module RuboCop
  module Cop
    module RSpec
      #  Checks for empty before and after hooks.
      #
      # @example
      #   # bad
      #   before {}
      #   after do; end
      #   before(:all) do
      #   end
      #   all(:all) { nil }
      #
      #   # good
      #   before { create_users }
      #   after do; cleanup_users; end
      #   before(:all) do
      #     create_feed
      #   end
      #   all(:all) { cleanup_feed }
      class EmptyHook < Cop
        MSG = 'Empty hook detected.'

        def_node_matcher :empty_hook?, <<~PATTERN
          (block
            $(send nil? {:before :after}
              (sym {:each :all :suite})?)
            _ {(:nil) nil?})
        PATTERN

        def on_block(node)
          empty_hook?(node) do |hook|
            add_offense(hook)
          end
        end
      end
    end
  end
end