[levenleven]

Summary

Slack sends app_rate_limited notifications as events_api envelopes with no inner event, which crashed the Socket Mode client with Cannot read properties of undefined (reading 'type'). The client now emits the payload type (e.g. app_rate_limited) for these messages. slack_event listeners still receive the message.

Fixes #2167
Fixes #2753

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

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🦋 Changeset detected

Latest commit: 0b075d5

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@slack/socket-mode	Patch

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.41%. Comparing base (8730b5e) to head (38a11ed).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2787      +/-   ##
==========================================
+ Coverage   89.34%   89.41%   +0.06%     
==========================================
  Files          65       65              
  Lines       10548    10560      +12     
  Branches      480      483       +3     
==========================================
+ Hits         9424     9442      +18     
+ Misses       1092     1086       -6     
  Partials       32       32              

Flag	Coverage Δ
cli-hooks	89.27% <100.00%> (-0.02%)	⬇️
cli-test	89.27% <100.00%> (-0.02%)	⬇️
logger	89.27% <100.00%> (-0.02%)	⬇️
oauth	89.27% <100.00%> (-0.02%)	⬇️
socket-mode	89.27% <100.00%> (-0.02%)	⬇️
web-api	89.27% <100.00%> (-0.02%)	⬇️
webhook	89.27% <100.00%> (-0.02%)	⬇️

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[hello-ashleyintech]

Thanks so much for tracking this down and putting together a fix — this crash has been open for a while and it's great to finally have a proper solution for it!

A couple of small things worth addressing before we merge:

Test consistency (SocketModeClient.test.ts) — the new tests skip the await sleep(30) that every other test in this file uses before asserting. Technically it works here since the emit() calls in onWebSocketMessage are synchronous (no await before them), but it'll look like an oversight to the next person reading these. Either add await sleep(30) to match the rest of the file, or drop a short comment explaining why it's not needed here.

Silent drop in the else branch (SocketModeClient.ts) — when event.payload?.type is absent, the new else if block just does nothing and moves on. That's fine as a fallback, but it makes future debugging harder if Slack ever sends another unexpected events_api shape. A quick this.logger.debug(...) in that case would go a long way toward diagnosing it without any real cost.

Neither of these is a blocker — the core fix is solid — but they're worth a quick pass before merge.

[levenleven]

Thanks for quick review @hello-ashleyintech. I've applied both suggestions.