Catch error if edited tech-support message has already been reacted to

ebmbot/bot.py

@@ -7,6 +7,7 @@
 from slack_bolt.adapter.socket_mode import SocketModeHandler
 from slack_bolt.error import BoltUnhandledRequestError
 from slack_bolt.util.utils import get_boot_message
+from slack_sdk.errors import SlackApiError
 
 from workspace.techsupport.jobs import get_dates_from_config as get_tech_support_dates
 
@@ -204,6 +205,10 @@ def _repost_to_tech_support(message, say, ack):
         # Don't repost messages in DMs with the bot
         if message["channel_type"] in ["channel", "group"]:
             # Respond with SOS reaction
+            # If we've already responded, the attempt to react here will raise
+            # an exception; if this happens, then the user is editing something
+            # other than the tech-support keyword in the message, and we don't need to
+            # repost it again. We let the default error handler will deal with it.
             app.client.reactions_add(
                 channel=message["channel"], timestamp=message["ts"], name="sos"
             )
@@ -239,15 +244,28 @@ def join_channel(event, ack):
 
     @app.error
     def handle_errors(error, body):
+        message_text = body["event"].get("message", {}).get("text", "")
         if isinstance(error, BoltUnhandledRequestError):
             # Unhandled messages are common (anything that doesn't get matched
             # by one of the listeners).  We don't want to log those.
             return BoltResponse(status=200, body="Unhandled message")
+        elif (
+            isinstance(error, SlackApiError)
+            and error.response.data["error"] == "already_reacted"
+            and "tech-support" in message_text
+        ):
+            # If we're already reacted to a tech-support message and the
+            # user edits the message, we get a slack error, but that's OK
+            logger.info(
+                "Already reacted to tech-support message",
+                message=message_text,
+            )
+            return BoltResponse(
+                status=200, body="Already reacted to tech-support message"
+            )
         else:
             # other error patterns
             channel = body["event"]["channel"]
-            message_text = body["event"].get("message", {}).get("text", "")
-
             ts = body["event"]["ts"]
             logger.error("Unexpected error", error=error, body=body)
             app.client.reactions_add(channel=channel, timestamp=ts, name="x")

tests/test_bot.py

@@ -1,10 +1,11 @@
 import json
 import time
 from datetime import datetime, timedelta
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
 import pytest
 from slack_bolt.request import BoltRequest
+from slack_sdk.errors import SlackApiError
 from slack_sdk.signature import SignatureVerifier
 
 from ebmbot import bot, scheduler
@@ -522,6 +523,55 @@ def test_unexpected_error(mock_app):
     )
 
 
+def test_already_reacted_to_tech_support_error(mock_app):
+    # mock an error from a method that's called during the tech-support
+    # handling to return an "already reacted" SlackApiError
+    with patch(
+        "ebmbot.bot.tech_support_out_of_office",
+        side_effect=SlackApiError(
+            message="Error", response=Mock(data={"error": "already_reacted"})
+        ),
+    ):
+        handle_message(
+            mock_app,
+            "tech-support help",
+            channel="channel",
+            reaction_count=1,
+            event_type="message",
+            expected_status=200,
+        )
+
+    assert_slack_client_sends_messages(
+        mock_app.recorder,
+        messages_kwargs=[],
+    )
+
+
+def test_already_reacted_to_non_tech_support_error(mock_app):
+    # Only already-reacted to tech support messages are ignored;
+    # another sort of message that raises this error gets
+    # reported back to slack
+    with patch(
+        "ebmbot.bot.handle_namespace_help",
+        side_effect=SlackApiError(
+            message="Error", response=Mock(data={"error": "already_reacted"})
+        ),
+    ):
+        handle_message(
+            mock_app, "<@U1234> test help", reaction_count=1, expected_status=500
+        )
+
+    assert_slack_client_sends_messages(
+        mock_app.recorder,
+        messages_kwargs=[
+            {
+                "channel": "channel",
+                "text": "Unexpected error: SlackApiError",
+            }
+        ],
+    )
+
+
 def test_new_channel_created(mock_app):
     # When a channel_created event is received, the bot user joins that channel
     handle_event(