3 files changed, 77 insertions, 0 deletions
diff --git a/rubocop/cop/include_action_view_context.rb b/rubocop/cop/include_action_view_context.rb
new file mode 100644
index 00000000000..14662a33e95
--- /dev/null
+++ b/rubocop/cop/include_action_view_context.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require_relative '../spec_helpers'
+
+module RuboCop
+  module Cop
+    # Cop that makes sure workers include `::Gitlab::ActionViewOutput::Context`, not `ActionView::Context`.
+    class IncludeActionViewContext < RuboCop::Cop::Cop
+      include SpecHelpers
+
+      MSG = 'Include `::Gitlab::ActionViewOutput::Context`, not `ActionView::Context`, for Rails 5.'.freeze
+
+      def_node_matcher :includes_action_view_context?, <<~PATTERN
+        (send nil? :include (const (const nil? :ActionView) :Context))
+      PATTERN
+
+      def on_send(node)
+        return if in_spec?(node)
+        return unless includes_action_view_context?(node)
+
+        add_offense(node.arguments.first, location: :expression)
+      end
+
+      def autocorrect(node)
+        lambda do |corrector|
+          corrector.replace(node.source_range, '::Gitlab::ActionViewOutput::Context')
+        end
+      end
+    end
+  end
+end
diff --git a/rubocop/rubocop.rb b/rubocop/rubocop.rb
index 50eab6f9270..ce6bdbf292c 100644
--- a/rubocop/rubocop.rb
+++ b/rubocop/rubocop.rb
@@ -4,6 +4,7 @@ require_relative 'cop/gitlab/predicate_memoization'
 require_relative 'cop/gitlab/httparty'
 require_relative 'cop/gitlab/finder_with_find_by'
 require_relative 'cop/gitlab/union'
+require_relative 'cop/include_action_view_context'
 require_relative 'cop/include_sidekiq_worker'
 require_relative 'cop/safe_params'
 require_relative 'cop/active_record_association_reload'
diff --git a/spec/rubocop/cop/include_action_view_context_spec.rb b/spec/rubocop/cop/include_action_view_context_spec.rb
new file mode 100644
index 00000000000..c888555b54f
--- /dev/null
+++ b/spec/rubocop/cop/include_action_view_context_spec.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+require 'rubocop'
+require 'rubocop/rspec/support'
+
+require_relative '../../../rubocop/cop/include_action_view_context'
+
+describe RuboCop::Cop::IncludeActionViewContext do
+  include CopHelper
+
+  subject(:cop) { described_class.new }
+
+  context 'when `ActionView::Context` is included' do
+    let(:source) { 'include ActionView::Context' }
+    let(:correct_source) { 'include ::Gitlab::ActionViewOutput::Context' }
+
+    it 'registers an offense' do
+      inspect_source(source)
+
+      aggregate_failures do
+        expect(cop.offenses.size).to eq(1)
+        expect(cop.offenses.map(&:line)).to eq([1])
+        expect(cop.highlights).to eq(['ActionView::Context'])
+      end
+    end
+
+    it 'autocorrects to the right version' do
+      autocorrected = autocorrect_source(source)
+
+      expect(autocorrected).to eq(correct_source)
+    end
+  end
+
+  context 'when `ActionView::Context` is not included' do
+    it 'registers no offense' do
+      inspect_source('include Context')
+
+      aggregate_failures do
+        expect(cop.offenses.size).to eq(0)
+      end
+    end
+  end
+end