1 files changed, 84 insertions, 0 deletions
diff --git a/rubocop/cop/rake/require.rb b/rubocop/cop/rake/require.rb
new file mode 100644
index 00000000000..e3e1696943d
--- /dev/null
+++ b/rubocop/cop/rake/require.rb
@@ -0,0 +1,84 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module Rake
+      # Flag global `require`s or `require_relative`s in rake files.
+      #
+      # Load dependencies lazily in `task` definitions if possible.
+      #
+      # @example
+      #   # bad
+      #
+      #   require_relative 'gitlab/json'
+      #   require 'json'
+      #
+      #   task :parse_json do
+      #     Gitlab::Json.parse(...)
+      #   end
+      #
+      #   # good
+      #
+      #   task :parse_json do
+      #     require_relative 'gitlab/json'
+      #     require 'json'
+      #
+      #     Gitlab::Json.parse(...)
+      #   end
+      #
+      #   RSpec::Core::RakeTask.new(:parse_json) do |t, args|
+      #     require_relative 'gitlab/json'
+      #     require 'json'
+      #
+      #     Gitlab::Json.parse(...)
+      #   end
+      #
+      #   # Requiring files which contain the word `task` is allowed.
+      #   require 'some_gem/rake_task'
+      #   require 'some_gem/rake_tasks'
+      #
+      #   SomeGem.define_tasks
+      #
+      #   # Loading in method definition as well.
+      #   def load_deps
+      #     require 'json'
+      #   end
+      #
+      #   task :parse_json
+      #     load_deps
+      #   end
+      #
+      class Require < RuboCop::Cop::Base
+        MSG = 'Load dependencies inside `task` definitions if possible.'
+
+        METHODS = %i[require require_relative].freeze
+        RESTRICT_ON_SEND = METHODS
+
+        def_node_matcher :require_method, <<~PATTERN
+          (send nil? ${#{METHODS.map(&:inspect).join(' ')}} $_)
+        PATTERN
+
+        def on_send(node)
+          method, file = require_method(node)
+          return unless method
+
+          return if requires_task?(file)
+          return if inside_block_or_method?(node)
+
+          add_offense(node)
+        end
+
+        private
+
+        # Allow `require "foo/rake_task"`
+        def requires_task?(file)
+          file.source.include?('task')
+        end
+
+        def inside_block_or_method?(node)
+          node.each_ancestor(:block, :def).any?
+        end
+      end
+    end
+  end
+end