Rails/ActionControllerFlashBeforeRender reports false positives with multiline if/else, redirect_to

[tagliala]

RuboCop reports a false positive with if/else and redirect_to

Follow up from #825

---

Expected behavior

Rubocop does not report errors

Actual behavior

Inspecting 1 file
C

Offenses:

rubocop_rails_825.rb:8:7: C: [Correctable] Rails/ActionControllerFlashBeforeRender: Use flash.now before render.
      flash[:success] = t('.flash.success') # false positive
      ^^^^^
rubocop_rails_825.rb:12:7: C: [Correctable] Rails/ActionControllerFlashBeforeRender: Use flash.now before render.
      flash[:alert] = t('.flash.fail') # false positive
      ^^^^^

1 file inspected, 2 offenses detected, 2 offenses autocorrectable

Steps to reproduce the problem

1. Create the following rubocop_rails_825.rb file

# frozen_string_literal: true

class PagesController < ApplicationController
  def destroy
    if @page.destroy
      do_something

      flash[:success] = t('.flash.success') # false positive
    else
      do_something_else

      flash[:alert] = t('.flash.fail') # false positive
    end

    redirect_to pages_path
  end
end

2. Run bundle exec rubocop --require rubocop-rails --only Rails/ActionControllerFlashBeforeRender rubocop_rails_825.rb

RuboCop version

$ bundle exec rubocop --require rubocop-rails -V
1.37.1 (using Parser 3.1.2.1, rubocop-ast 1.23.0, running on ruby 3.0.4) [x86_64-darwin22]
  - rubocop-rails 2.17.2

Also tested against rubocop-rails main