UX: Apply decorators to small action posts (#24397)

plugins/discourse-local-dates/spec/system/post_small_action_spec.rb

@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+describe "Post small actions", type: :system do
+  fab!(:current_user) { Fabricate(:user) }
+  fab!(:topic) { Fabricate(:topic) }
+  fab!(:post) { Fabricate(:post, topic: topic) }
+  let(:topic_page) { PageObjects::Pages::Topic.new }
+
+  before { sign_in(current_user) }
+
+  it "applies local date decorations" do
+    post =
+      Fabricate(
+        :small_action,
+        raw: "[date=2023-11-15 timezone=\"America/Los_Angeles\"] a date",
+        topic: topic,
+      )
+
+    topic_page.visit_topic(topic)
+    expect(topic_page).to have_post_number(post.post_number)
+
+    expect(page).to have_css(".small-action-custom-message .discourse-local-date.cooked-date")
+  end
+end