flash discard for now only

app/controllers/application_controller.rb

@@ -3,9 +3,7 @@ class ApplicationController < ActionController::Base
   allow_browser versions: :modern
 
   def render_stream(notice: nil, alert: nil, &)
-    flash.now[:notice] = notice if notice
-    flash.now[:alert] = alert if alert
-
+    flash_now_only!(notice, alert)
     proxy_stream = ProxyStream.new(turbo_stream)
     proxy_stream.replace(:flash, partial: 'layouts/components/flash') if flash.any?
     yield(proxy_stream) if block_given?
@@ -29,4 +27,12 @@ class ApplicationController < ActionController::Base
     end
   end
   private_constant(:ProxyStream)
+
+  private
+
+  def flash_now_only!(notice, alert)
+    flash.discard
+    flash.now[:notice] = notice if notice
+    flash.now[:alert] = alert if alert
+  end
 end