DEV: send_chat_message supports topic_tags_changed (#28755)

This will allow admins to use this script and trigger together.

plugins/chat/plugin.rb

@@ -452,7 +452,6 @@ after_initialize do
         }
   end
 
-  if defined?(DiscourseAutomation)
   add_automation_scriptable("send_chat_message") do
     field :chat_channel_id, component: :text, required: true
     field :message, component: :message, required: true, accepts_placeholders: true
@@ -460,12 +459,11 @@ after_initialize do
 
     placeholder :channel_name
 
-      triggerables [:recurring]
+    triggerables %i[recurring topic_tags_changed]
 
     script do |context, fields, automation|
       sender = User.find_by(username: fields.dig("sender", "value")) || Discourse.system_user
       channel = Chat::Channel.find_by(id: fields.dig("chat_channel_id", "value"))
-
       placeholders = { channel_name: channel.title(sender) }.merge(context["placeholders"] || {})
 
       creator =
@@ -480,7 +478,6 @@ after_initialize do
       end
     end
   end
-  end
 
   add_api_key_scope(
     :chat,

plugins/chat/spec/plugin_spec.rb

@@ -339,4 +339,52 @@ describe Chat do
       ).by(1)
     end
   end
+
+  describe "when using topic tags changed trigger automation" do
+    describe "with the send message script" do
+      fab!(:automation_1) do
+        Fabricate(
+          :automation,
+          trigger: DiscourseAutomation::Triggers::TOPIC_TAGS_CHANGED,
+          script: :send_chat_message,
+        )
+      end
+      fab!(:tag_1) { Fabricate(:tag) }
+      fab!(:user_1) { Fabricate(:admin) }
+      fab!(:topic_1) { Fabricate(:topic) }
+      fab!(:channel_1) { Fabricate(:chat_channel) }
+
+      before do
+        SiteSetting.discourse_automation_enabled = true
+        SiteSetting.tagging_enabled = true
+
+        automation_1.upsert_field!(
+          "watching_tags",
+          "tags",
+          { value: [tag_1.name] },
+          target: "trigger",
+        )
+        automation_1.upsert_field!(
+          "chat_channel_id",
+          "text",
+          { value: channel_1.id },
+          target: "script",
+        )
+        automation_1.upsert_field!(
+          "message",
+          "message",
+          { value: "[{{topic_title}}]({{topic_url}})" },
+          target: "script",
+        )
+      end
+
+      it "sends the message" do
+        DiscourseTagging.tag_topic_by_names(topic_1, Guardian.new(user_1), [tag_1.name])
+
+        expect(channel_1.chat_messages.last.message).to eq(
+          "[#{topic_1.title}](#{topic_1.relative_url})",
+        )
+      end
+    end
+  end
 end