From 5c3bcafb77ca4eb564f99c843a488343d0ff2015 Mon Sep 17 00:00:00 2001
From: Mohammad Abdul Sahil <127765312+abdulsaheel@users.noreply.github.com>
Date: Sat, 19 Sep 2026 02:19:26 +0530
Subject: [PATCH] gate select_wrist decode on cmd_status like the other
 confirmation replies

a failed select_wrist write still returned a SelectWristResponse built from
stale payload bytes, no different from the fixed getBatteryPackInfo/getHello
cases. added the status==1 check + a test for the failure case.
---
 lib/src/control.dart                 | 15 +++++++++++----
 test/whoop_protocol_update_test.dart | 10 ++++++++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/lib/src/control.dart b/lib/src/control.dart
index df4b94c..5334635 100644
--- a/lib/src/control.dart
+++ b/lib/src/control.dart
@@ -1001,10 +1001,17 @@ CmdResponse? parseCommandResponse(Uint8List inner,
   } else if ((op == Cmd.enterHighFreqSync || op == Cmd.exitHighFreqSync)) {
     dec['high_freq_sync'] = HighFreqSyncResponse(op);
   } else if (op == Cmd.selectWrist && payload.length >= 3) {
-    dec['select_wrist'] = SelectWristResponse(
-      revision: payload[2],
-      payload: Uint8List.fromList(payload.sublist(2)),
-    );
+    // Status-gated like getHello above: this is a SET-style confirmation,
+    // and a failure reply does not populate the body, so its bytes are
+    // stale. Without the check a rejected wrist-selection write (bad value,
+    // or refused mid-handshake) would still mint a `select_wrist` object
+    // that looks like confirmation the selection took effect.
+    if (status == 1) {
+      dec['select_wrist'] = SelectWristResponse(
+        revision: payload[2],
+        payload: Uint8List.fromList(payload.sublist(2)),
+      );
+    }
   } else if (op == Cmd.getBatteryPackInfo && payload.length >= 30) {
     // 28-byte body [rev][attached][id ×6][name ×16][u16][type][status], again
     // starting at payload[2]. Every field was previously read two bytes early,
diff --git a/test/whoop_protocol_update_test.dart b/test/whoop_protocol_update_test.dart
index eb3ff13..aafba3e 100644
--- a/test/whoop_protocol_update_test.dart
+++ b/test/whoop_protocol_update_test.dart
@@ -259,6 +259,16 @@ void main() {
       expect(ack.revision, 1);
       expect(ack.payload, [0x01, 0x02]);
     });
+
+    test('0x7b select wrist response is dropped when cmd_status is not ok',
+        () {
+      // Same stale-but-plausible body as above, but cmd_status = 0 (failed)
+      // — a failure reply's body is unpopulated, so these bytes must not be
+      // trusted as confirmation the wrist selection took effect.
+      final inner = hexToBytes('24037b' '0700' '0102');
+      final resp = parseCommandResponse(inner)!;
+      expect(resp.decoded.containsKey('select_wrist'), isFalse);
+    });
   });
 
   group('WHOOP realtime HR revision 2', () {