1 files changed, 50 insertions, 0 deletions
diff --git a/rubocop/cop/rspec/modify_sidekiq_middleware.rb b/rubocop/cop/rspec/modify_sidekiq_middleware.rb
new file mode 100644
index 00000000000..c38f074eb3a
--- /dev/null
+++ b/rubocop/cop/rspec/modify_sidekiq_middleware.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module RuboCop
+  module Cop
+    module RSpec
+      # This cop checks for `Sidekiq::Testing.server_middleware`
+      # usage in specs.
+      #
+      # @example
+      #
+      #   # bad
+      #   Sidekiq::Testing.server_middleware do |chain|
+      #     chain.add(MyMiddlewareUnderTest)
+      #   end
+      #
+      #
+      #   # good
+      #   with_custom_sidekiq_middleware do |chain|
+      #     chain.add(MyMiddlewareUnderTest)
+      #   end
+      #
+      #
+      class ModifySidekiqMiddleware < RuboCop::Cop::Cop
+        MSG = <<~MSG
+          Don't modify global sidekiq middleware, use the `#with_sidekiq_server_middleware`
+          helper instead
+        MSG
+
+        def_node_search :modifies_sidekiq_middleware?, <<~PATTERN
+          (send
+            (const
+              (const nil? :Sidekiq) :Testing) :server_middleware)
+        PATTERN
+
+        def on_send(node)
+          return unless modifies_sidekiq_middleware?(node)
+
+          add_offense(node, location: :expression)
+        end
+
+        def autocorrect(node)
+          -> (corrector) do
+            corrector.replace(node.loc.expression,
+                              'with_sidekiq_server_middleware')
+          end
+        end
+      end
+    end
+  end
+end