DEV: Refactor a little chat uploads

This is extracted from #22390.

This patch simplifies a little how we handle uploads in chat, relying on
ActiveRecord mechanisms instead of calling custom methods.

This also makes `Chat::Message#validate_message` a “real” AR validation,
meaning it will run automatically when `#valid?` is called.

plugins/chat/spec/lib/chat/transcript_service_spec.rb

@@ -118,7 +118,6 @@ describe Chat::TranscriptService do
 
   it "generates image / attachment / video / audio markdown inside the [chat] bbcode for upload-only messages" do
     SiteSetting.authorized_extensions = "mp4|mp3|pdf|jpg"
-    message = Fabricate(:chat_message, user: user1, chat_channel: channel, message: "")
     video = Fabricate(:upload, original_filename: "test_video.mp4", extension: "mp4")
     audio = Fabricate(:upload, original_filename: "test_audio.mp3", extension: "mp3")
     attachment = Fabricate(:upload, original_filename: "test_file.pdf", extension: "pdf")
@@ -130,10 +129,14 @@ describe Chat::TranscriptService do
         original_filename: "test_img.jpg",
         extension: "jpg",
       )
-    UploadReference.create(target: message, created_at: 10.seconds.ago, upload: video)
-    UploadReference.create(target: message, created_at: 9.seconds.ago, upload: audio)
-    UploadReference.create(target: message, created_at: 8.seconds.ago, upload: attachment)
-    UploadReference.create(target: message, created_at: 7.seconds.ago, upload: image)
+    message =
+      Fabricate(
+        :chat_message,
+        user: user1,
+        chat_channel: channel,
+        message: "",
+        uploads: [video, audio, attachment, image],
+      )
     video_markdown = UploadMarkdown.new(video).to_markdown
     audio_markdown = UploadMarkdown.new(audio).to_markdown
     attachment_markdown = UploadMarkdown.new(attachment).to_markdown

plugins/chat/spec/models/chat/message_spec.rb

@@ -293,8 +293,7 @@ describe Chat::Message do
     it "excerpts upload file name if message is empty" do
       gif =
         Fabricate(:upload, original_filename: "cat.gif", width: 400, height: 300, extension: "gif")
-      message = Fabricate(:chat_message, message: "")
-      message.attach_uploads([gif])
+      message = Fabricate(:chat_message, message: "", uploads: [gif])
 
       expect(message.excerpt).to eq "cat.gif"
     end
@@ -377,7 +376,7 @@ describe Chat::Message do
         )
       image2 =
         Fabricate(:upload, original_filename: "meme.jpg", width: 10, height: 10, extension: "jpg")
-      message.attach_uploads([image, image2])
+      message.uploads = [image, image2]
       expect(message.to_markdown).to eq(<<~MSG.chomp)
       hey friend, what's up?!
 
@@ -410,7 +409,7 @@ describe Chat::Message do
       Fabricate(:chat_message, message: "this is duplicate", chat_channel: channel, user: user1)
       message =
         described_class.new(message: "this is duplicate", chat_channel: channel, user: user2)
-      message.validate_message(has_uploads: false)
+      message.valid?
       expect(message.errors.full_messages).to include(I18n.t("chat.errors.duplicate_message"))
     end
   end
@@ -526,30 +525,6 @@ describe Chat::Message do
     end
   end
 
-  describe "#attach_uploads" do
-    fab!(:chat_message) { Fabricate(:chat_message) }
-    fab!(:upload_1) { Fabricate(:upload) }
-    fab!(:upload_2) { Fabricate(:upload) }
-
-    it "creates an UploadReference record for the provided uploads" do
-      chat_message.attach_uploads([upload_1, upload_2])
-      upload_references = UploadReference.where(upload_id: [upload_1, upload_2])
-      expect(upload_references.count).to eq(2)
-      expect(upload_references.map(&:target_id).uniq).to eq([chat_message.id])
-      expect(upload_references.map(&:target_type).uniq).to eq([described_class.polymorphic_name])
-    end
-
-    it "does nothing if the message record is new" do
-      expect { described_class.new.attach_uploads([upload_1, upload_2]) }.to not_change {
-        UploadReference.count
-      }
-    end
-
-    it "does nothing for an empty uploads array" do
-      expect { chat_message.attach_uploads([]) }.to not_change { UploadReference.count }
-    end
-  end
-
   describe "#create_mentions" do
     fab!(:message) { Fabricate(:chat_message) }
     fab!(:user1) { Fabricate(:user) }

plugins/chat/spec/system/channel_message_upload_spec.rb

@@ -21,7 +21,7 @@ RSpec.describe "Channel message selection", type: :system do
     chat_system_bootstrap
     channel_1.add(current_user)
     sign_in(current_user)
-    message_1.attach_uploads([image])
+    message_1.uploads = [image]
   end
 
   it "can collapse/expand an image and still have lightbox working" do