False positive in Rails/ActionControllerFlashBeforeRender when using multiple flashes + conditions

[jamescook]

---

Expected behavior

This code should be valid:

        class HomeController < ApplicationController
          def update
            if condition
              flash[:danger] = "msg"
              redirect_to root_path and return
            end

            if other_condition
              flash[:success] = "other msg"
              redirect_to root_path
            else
              flash.now[:danger] = "other other msg"
              render 'something', status: :unprocessable_entity
            end
          end
        end

Actual behavior

Rubocop says to use flash.now before render, which I think is wrong:

          def update
            if condition
              flash[:danger] = "msg"
       +      ^^^^^ Use `flash.now` before `render`.
              redirect_to root_path and return
            end

Steps to reproduce the problem

--- a/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb
+++ b/spec/rubocop/cop/rails/action_controller_flash_before_render_spec.rb
@@ -328,4 +328,27 @@ RSpec.describe RuboCop::Cop::Rails::ActionControllerFlashBeforeRender, :config d
       RUBY
     end
   end
+
+  context 'when using `flash` before `render` and returning `redirect_to` in condition block - part deux' do
+    it 'does not register an offense' do
+      expect_no_offenses(<<~RUBY)
+        class HomeController < ApplicationController
+          def update
+            if condition
+              flash[:danger] = "msg" # breaks here
+              redirect_to root_path and return
+            end
+
+            if other_condition
+              flash[:success] = "other msg"
+              redirect_to root_path
+            else
+              flash.now[:danger] = "other other msg"
+              render 'something', status: :unprocessable_entity
+            end
+          end
+        end
+      RUBY
+    end
+  end

Spec passes if I change the example code to use return redirect_to root_path inside the offending condition so I suspect it's related to the usage of redirect_to ... and return. However, the spec will pass when using redirect_to root_path and return if I remove the code starting with if other_condition through the end of the Rails action.

RuboCop version

bundle exec rubocop -V
1.63.1 (using Parser 3.3.0.5, rubocop-ast 1.31.2, running on ruby 3.1.4) [arm64-darwin22]

• rubocop-performance 1.21.0
• rubocop-rails 2.24.1
• rubocop-rspec 2.27.1