Slackbot: per-message dedupe; ignore only edits while in-progress (#1226)

* slackbot: remove locals() hack; clean root completion mark; fix duplicate bot_auth line

* slackbot: dedupe per-message (ts), detect edits via message_changed; ignore only edits while in-progress\n\n- Parse edit events (event.subtype == message_changed) including nested message.ts/text\n- Use message_ts as idempotency key so replies/new mentions are unaffected\n- Post polite notice only on edit duplicates; skip quiet otherwise\n- Mark completion by message key

* address copilot review: robust fallbacks for message_ts/thread_ts on edit and non-edit events

* refactor: extract edit/non-edit parsing into helper; remove repeated (event.message or {}) usage per Copilot feedback

Author: zzstoatzz

examples/slackbot/src/slackbot/api.py

@@ -118,6 +118,33 @@ async def run_agent(
         raise
 
 
+def _extract_message_context(event: Any) -> tuple[bool, str | None, str | None, str]:
+    """Return (is_edit, message_ts, thread_ts, text) for Slack events.
+
+    - For `message_changed` events, Slack nests the edited message under `event.message`.
+    - For normal app_mention events, fields are at the top level.
+    """
+    is_edit = getattr(event, "subtype", None) == "message_changed"
+    msg = (getattr(event, "message", None) or {}) if is_edit else {}
+
+    # Prefer the message ts for idempotency; fall back to event_ts if needed
+    message_ts = (
+        msg.get("ts")
+        if is_edit
+        else (getattr(event, "ts", None) or getattr(event, "event_ts", None))
+    )
+    # Thread anchor where we should post replies
+    thread_ts = (
+        (msg.get("thread_ts") or msg.get("ts"))
+        if is_edit
+        else (getattr(event, "thread_ts", None) or getattr(event, "ts", None))
+    )
+    # Text used for bot mention detection
+    text = (msg.get("text") if is_edit else (getattr(event, "text", None) or "")) or ""
+
+    return is_edit, message_ts, thread_ts, text
+
+
 @flow(name="Handle Slack Message", retries=1)
 async def handle_message(payload: SlackPayload, db: Database):
     logger = get_run_logger()
@@ -127,9 +154,10 @@ async def handle_message(payload: SlackPayload, db: Database):
         return Completed(message="Invalid event", name="SKIPPED")
 
     USER_MESSAGE_MAX_TOKENS = settings.user_message_max_tokens
-    user_message = event.text or ""
-    thread_ts = event.thread_ts or event.ts
+    # Determine message context accommodating edit events
+    is_edit, message_ts, thread_ts, user_message = _extract_message_context(event)
     assert thread_ts is not None, "No thread_ts found"
+    assert message_ts is not None, "No message_ts found"
     cleaned_message = re.sub(BOT_MENTION, "", user_message).strip()
     msg_len = count_tokens(cleaned_message)
 
@@ -149,38 +177,33 @@ async def handle_message(payload: SlackPayload, db: Database):
         return Completed(message="Message too long", name="SKIPPED")
 
     if re.search(BOT_MENTION, user_message) and payload.authorizations:
-        # Only gate the root message; replies should not be blocked
-        is_root_message = event.thread_ts is None
-        root_ts = thread_ts
-
-        if is_root_message:
-            # Cross-process acquire; only one handler should proceed for the root
-            acquired = await try_acquire_thread(db, root_ts)
-            if not acquired:
-                status = await get_thread_status(db, root_ts)
-                if status == "in_progress":
-                    assert event.channel is not None, (
-                        "Event channel is None when posting edit-ignored notice"
-                    )
-                    await post_slack_message(
-                        message=(
-                            "✋ I noticed you edited your original message. "
-                            "I'm already working on your first version — please add any "
-                            "clarifications as new messages in this thread so I don't lose track."
-                        ),
-                        channel_id=event.channel,
-                        thread_ts=root_ts,
-                    )
-                    return Completed(
-                        message="Ignored edit while in progress",
-                        name="IGNORED_EDIT",
-                        data=dict(thread_ts=root_ts),
-                    )
+        # Per-message acquire: prevent duplicate handling for this specific message
+        acquired = await try_acquire_thread(db, message_ts)
+        if not acquired:
+            status = await get_thread_status(db, message_ts)
+            if status == "in_progress" and is_edit:
+                assert event.channel is not None, (
+                    "Event channel is None when posting edit-ignored notice"
+                )
+                await post_slack_message(
+                    message=(
+                        "✋ I noticed you edited your original message. "
+                        "I'm already working on your first version — please add any "
+                        "clarifications as new messages in this thread so I don't lose track."
+                    ),
+                    channel_id=event.channel,
+                    thread_ts=thread_ts,
+                )
                 return Completed(
-                    message="Duplicate root event after completion",
-                    name="SKIPPED_DUPLICATE",
-                    data=dict(thread_ts=root_ts),
+                    message="Ignored edit while in progress",
+                    name="IGNORED_EDIT",
+                    data=dict(message_ts=message_ts, thread_ts=thread_ts),
                 )
+            return Completed(
+                message="Duplicate event for message",
+                name="SKIPPED_DUPLICATE",
+                data=dict(message_ts=message_ts, thread_ts=thread_ts),
+            )
 
         # Check if this is the designated channel
         team_id = payload.team_id or ""
@@ -263,12 +286,10 @@ async def handle_message(payload: SlackPayload, db: Database):
                 data=dict(error=str(e), user_context=user_context),
             )
         finally:
-            # Only mark completion for the root message; do not block replies
-            if "is_root_message" in locals() and is_root_message:
-                try:
-                    await mark_thread_completed(db, root_ts)
-                except Exception:
-                    logger.warning("Failed to mark thread as completed")
+            try:
+                await mark_thread_completed(db, message_ts)
+            except Exception:
+                logger.warning("Failed to mark message as completed")
 
         return Completed(
             message="Responded to mention",

examples/slackbot/src/slackbot/slack.py

@@ -31,6 +31,8 @@ class SlackEvent(BaseModel):
     type: str
     subtype: str | None = None
     text: str | None = None
+    # For message_changed edit events, Slack nests the edited message here
+    message: dict[str, Any] | None = None
     user: str | dict[str, Any] | None = None
     ts: str | None = None
     team: str | None = None