FIX: Check post action creator result when flagging spam (#1119)

Currently in core re-flagging something that is already flagged as spam
is not supported, long term we may want to support this but in the meantime
we should not be silencing/hiding if the PostActionCreator fails
when flagging things as spam.

---------

Co-authored-by: Ted Johansson <[email protected]>

Author: martin-brennan

app/models/ai_spam_log.rb

@@ -19,6 +19,7 @@ class AiSpamLog < ActiveRecord::Base
 #  payload             :string(20000)    default(""), not null
 #  created_at          :datetime         not null
 #  updated_at          :datetime         not null
+#  error               :string(3000)
 #
 # Indexes
 #

db/migrate/20250211021037_add_error_to_ai_spam_log.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+class AddErrorToAiSpamLog < ActiveRecord::Migration[7.2]
+  def change
+    add_column :ai_spam_logs, :error, :string, limit: 3000
+  end
+end

lib/ai_moderation/spam_scanner.rb

@@ -394,22 +394,32 @@ def self.handle_spam(post, log)
             queue_for_review: true,
           ).perform
 
-        log.update!(reviewable: result.reviewable)
+        # Currently in core re-flagging something that is already flagged as spam
+        # is not supported, long term we may want to support this but in the meantime
+        # we should not be silencing/hiding if the PostActionCreator fails.
+        if result.success?
+          log.update!(reviewable: result.reviewable)
+
+          reason = I18n.t("discourse_ai.spam_detection.silence_reason", url: url)
+          silencer =
+            UserSilencer.new(
+              post.user,
+              flagging_user,
+              message: :too_many_spam_flags,
+              post_id: post.id,
+              reason: reason,
+              keep_posts: true,
+            )
+          silencer.silence
 
-        reason = I18n.t("discourse_ai.spam_detection.silence_reason", url: url)
-        silencer =
-          UserSilencer.new(
-            post.user,
-            flagging_user,
-            message: :too_many_spam_flags,
-            post_id: post.id,
-            reason: reason,
-            keep_posts: true,
+          # silencer will not hide tl1 posts, so we do this here
+          hide_post(post)
+        else
+          log.update!(
+            error:
+              "unable to flag post as spam, post action failed for post #{post.id} with error: '#{result.errors.full_messages.join(", ").truncate(3000)}'",
           )
-        silencer.silence
-
-        # silencer will not hide tl1 posts, so we do this here
-        hide_post(post)
+        end
       end
 
       def self.hide_post(post)

lib/automation/llm_triage.rb

@@ -88,15 +88,24 @@ def self.handle(
                 .sub("%%AUTOMATION_NAME%%", automation&.name.to_s)
 
             if flag_type == :spam || flag_type == :spam_silence
-              PostActionCreator.new(
-                Discourse.system_user,
-                post,
-                PostActionType.types[:spam],
-                message: score_reason,
-                queue_for_review: true,
-              ).perform
+              result =
+                PostActionCreator.new(
+                  Discourse.system_user,
+                  post,
+                  PostActionType.types[:spam],
+                  message: score_reason,
+                  queue_for_review: true,
+                ).perform
 
-              SpamRule::AutoSilence.new(post.user, post).silence_user if flag_type == :spam_silence
+              if flag_type == :spam_silence
+                if result.success?
+                  SpamRule::AutoSilence.new(post.user, post).silence_user
+                else
+                  Rails.logger.warn(
+                    "llm_triage: unable to flag post as spam, post action failed for #{post.id} with error: '#{result.errors.full_messages.join(",").truncate(3000)}'",
+                  )
+                end
+              end
             else
               reviewable =
                 ReviewablePost.needs_review!(target: post, created_by: Discourse.system_user)

spec/lib/modules/ai_moderation/spam_scanner_spec.rb

@@ -214,7 +214,7 @@
 
     before { Jobs.run_immediately! }
 
-    it "Can correctly run tests" do
+    it "can correctly run tests" do
       prompts = nil
       result =
         DiscourseAi::Completions::Llm.with_prepared_responses(
@@ -240,7 +240,7 @@
       expect(result[:is_spam]).to eq(false)
     end
 
-    it "Correctly handles spam scanning" do
+    it "correctly handles spam scanning" do
       expect(described_class.flagging_user.id).not_to eq(Discourse.system_user.id)
 
       # flag post for scanning
@@ -288,6 +288,30 @@
       expect(post.topic.reload.visible).to eq(true)
       expect(post.user.reload.silenced?).to eq(false)
     end
+
+    it "does not silence the user or hide the post when a flag cannot be created" do
+      post = post_with_uploaded_image
+      Fabricate(
+        :post_action,
+        post: post,
+        user: described_class.flagging_user,
+        post_action_type_id: PostActionType.types[:spam],
+      )
+
+      described_class.new_post(post)
+
+      DiscourseAi::Completions::Llm.with_prepared_responses(["spam"]) do |_, _, _prompts|
+        # force a rebake so we actually scan
+        post.rebake!
+      end
+
+      log = AiSpamLog.find_by(post: post)
+
+      expect(log.reviewable).to be_nil
+      expect(log.error).to match(/unable to flag post as spam/)
+      expect(post.user.reload).not_to be_silenced
+      expect(post.topic.reload).to be_visible
+    end
   end
 
   it "includes location information and email in context" do

spec/lib/modules/automation/llm_triage_spec.rb

@@ -128,6 +128,28 @@ def triage(**args)
     expect(post.user.silenced?).to eq(true)
   end
 
+  it "does not silence the user if the flag fails" do
+    Fabricate(
+      :post_action,
+      post: post,
+      user: Discourse.system_user,
+      post_action_type_id: PostActionType.types[:spam],
+    )
+    DiscourseAi::Completions::Llm.with_prepared_responses(["bad"]) do
+      triage(
+        post: post,
+        model: "custom:#{llm_model.id}",
+        system_prompt: "test %%POST%%",
+        search_for_text: "bad",
+        flag_post: true,
+        flag_type: :spam_silence,
+        automation: nil,
+      )
+    end
+
+    expect(post.user.reload).not_to be_silenced
+  end
+
   it "can handle garbled output from LLM" do
     DiscourseAi::Completions::Llm.with_prepared_responses(["Bad.\n\nYo"]) do
       triage(