Include the content of the flash in the auto-generated etag (#26250)

Include the content of the flash in the auto-generated etag

1 files changed, 16 insertions, 0 deletions

diff --git a/actionpack/lib/action_controller/metal/etag_with_flash.rb b/actionpack/lib/action_controller/metal/etag_with_flash.rb
new file mode 100644
index 0000000000..474d75f02e
--- /dev/null
+++ b/actionpack/lib/action_controller/metal/etag_with_flash.rb
@@ -0,0 +1,16 @@
+module ActionController
+  # When you're using the flash, it's generally used as a conditional on the view.
+  # This means the content of the view depends on the flash. Which in turn means
+  # that the etag for a response should be computed with the content of the flash
+  # in mind. This does that by including the content of the flash as a component
+  # in the etag that's generated for a response.
+  module EtagWithFlash
+    extend ActiveSupport::Concern
+
+    include ActionController::ConditionalGet
+
+    included do
+      etag { flash unless flash.empty? }
+    end
+  end
+end