[InDate]

Summary

parsePacket searched for the suffix from byte 0. The sequence field sits inside that range, so a sequence number of 0x0000AA55, or 0x00009966 on 3.5, produces a match there. The buffer is cut to 8 or 10 bytes, and the next readUInt32BE throws ERR_OUT_OF_RANGE. Every device whose counter reaches those values drops that frame.

 parsePacket(buffer)
   prefix = buffer.readUInt32BE(0)
-  suffixLocation = buffer.indexOf('0000AA55') ?? buffer.indexOf('00009966')
-  cut buffer at suffixLocation + 4
+  frameLength = prefix === 0x6699
+    ? buffer.readUInt32BE(14) + 22   // header 18 + length + suffix 4
+    : buffer.readUInt32BE(12) + 16   // header 16 + length
+  buffer shorter than frameLength -> throw "Packet missing payload"
+  cut buffer at frameLength, rest to leftover
   suffix check, sequence, command, payload as before

The lengths match what _encodePre34, _encode34 and _encode35 write.

Evidence

Found on a 3.5 light, Version: 3.5:

The value of "offset" is out of range. It must be >= 0 and <= 6. Received 8

New tests in test/parser.js: for protocols 3.1, 3.3, 3.4 and 3.5 and sequence numbers 0xaa55 and 0x9966, two packets back to back parse as 2 packets, each with its sequence number, command and payload.

• Before (master): 5 of the 8 fail with ERR_OUT_OF_RANGE: 0xaa55 on all four protocols, and 0x9966 on 3.5.
  After: npm test on Node 22.23.2: 47 tests passed. npm run lint: 0 errors, the same 2 warnings as master; the parsePacket complexity warning moves from 31 to 32.

The patched build has run on a Homey Pro with 3.3 and 3.5 devices, and the light reports its state as before.

Merge Danger

Door: two-way

Blast Radius: parsing

Every received frame now goes through the length field. A device whose length field disagrees with its actual frame size used to parse when the suffix sat at the end. With this change it throws "Packet missing payload", or its trailing bytes go to leftover. The encoders and the existing payload-size checks already depend on that field.

https://claude.ai/code/session_01Mi7yrmdxpownpnTsMGLHJW