False positive for ActionControllerFlashBeforeRender when flash is called in a block

[HashNotAdam]

When flash is called inside a block, a violation of Rails/ActionControllerFlashBeforeRender is thrown even when the action calls redirect_to.

---

Expected behavior

A violation should not occur when a redirect is being performed

Actual behavior

Even in a clean action (i.e. no control flow where sometimes it renders and sometimes it redirects), a violation is raised.

Steps to reproduce the problem

This action is reported as violating the rule:

def test
  messages = %w[a b c d]
  messages.each { flash[:error] = _1 }

  redirect_to(some_path)
end

The same problem occurs when called in a multi-line block:

def test
  messages = %w[a b c d]
  messages.each do |message|
    flash[:error] = message
  end

  redirect_to(some_path)
end

The issue does not occur if you assign the array directly to flash:

def test
  messages = %w[a b c d]
  flash[:error] = messages

  redirect_to(some_path)
end

RuboCop version

1.56.4 (using Parser 3.2.2.4, rubocop-ast 1.30.0, running on ruby 3.2.2) [arm64-darwin23]
  - rubocop-factory_bot 2.24.0
  - rubocop-i18n 1.14.1
  - rubocop-performance 1.19.1
  - rubocop-rails 2.22.1
  - rubocop-rspec 2.24.1