Add UTS tests for LiveObjects path-based API

test/uts/deviations.md

@@ -216,6 +216,78 @@ These tests assert spec behavior but are skipped by default because they are kno
 
 ---
 
+## Adapted Deviations (tests modified to match ably-js behavior)
+
+These tests have been adapted from the UTS spec to account for ably-js API differences. The test still validates the underlying behavior but uses ably-js's actual API surface.
+
+### objects/live_object_subscribe: RTLO4b4d - objectMessage exposed as `.message`
+
+**Spec (RTLO4b4d)**: `LiveObjectUpdate.objectMessage` carries the source ObjectMessage.
+
+**ably-js behavior**: `InstanceSubscriptionEvent` exposes the public ObjectMessage as `.message` (not `.objectMessage`). The operation action is a string (`'counter.inc'`) instead of the internal numeric constant.
+
+**Test**: Adapted to use `updates[0].message` and string action names.
+
+---
+
+### objects/live_object_subscribe: RTLO4b4e - tombstone flag not on InstanceSubscriptionEvent
+
+**Spec (RTLO4b4e)**: `LiveObjectUpdate.tombstone` indicates whether the update was a tombstone.
+
+**ably-js behavior**: `InstanceSubscriptionEvent` does not expose a `tombstone` field. The tombstone behavior (deregistering listeners) works internally, but is not surfaced to the user-facing event.
+
+**Test**: Adapted to verify the event is delivered and check the operation action (`'object.delete'` for tombstone, `'counter.inc'` for normal) instead of asserting `.tombstone`.
+
+---
+
+### objects/live_object_subscribe: RTLO4b4c3c - tombstone flag not checkable
+
+**Spec (RTLO4b4c3c)**: Tombstone update deregisters all listeners, and `update.tombstone == true`.
+
+**ably-js behavior**: Tombstone deregistration works correctly (subsequent events do not fire), but `InstanceSubscriptionEvent` does not expose `.tombstone`. Test adapted to skip the `.tombstone` assertion.
+
+---
+
+### objects/realtime_object: RTO15 - publish result serials not exposed
+
+**Spec (RTO15)**: `publish()` returns `PublishResult` with `.serials`.
+
+**ably-js behavior**: PathObject mutation methods (`increment`, `set`, etc.) return `void` via `publishAndApply`. The `PublishResult.serials` are consumed internally for apply-on-ACK and not returned to the caller.
+
+**Test**: Removed `result.serials` assertion.
+
+---
+
+### objects/realtime_object: RTO25b/RTO26b - channel.object.get() re-attaches on DETACHED
+
+**Spec (RTO25b/RTO26b)**: Access/write API should throw 90001 on DETACHED channel.
+
+**ably-js behavior**: `channel.object.get()` calls `ensureAttached()` which re-attaches for DETACHED. The precondition check (`throwIfInvalidAccessApiConfiguration`) is on PathObject/Instance methods, not on `channel.object.get()`.
+
+**Test**: Adapted to call `root.value()` / `root.set()` instead of `channel.object.get()` to trigger the precondition.
+
+---
+
+### objects/realtime_object: RTO24c1 - depth semantics
+
+**Spec (RTO24c1)**: `depth: 1` covers "root and immediate children".
+
+**ably-js behavior**: Depth counts the subscription level itself as depth 1. So `depth: 2` means "self + direct children" (matching the spec's `depth: 1` semantics). Also, `PathObject.subscribe(listener, options?)` takes listener first, not options first.
+
+**Test**: Adapted to use `depth: 2` and correct argument order.
+
+---
+
+### objects/instance: RTINS16e2 - MAP_SET serial must exceed entry timeserial
+
+**Spec (RTINS16e2)**: Tests InstanceSubscriptionEvent.message from a MAP_SET operation.
+
+**ably-js behavior**: MAP_SET uses LWW conflict resolution with string-compared serials. The test's original serial `'99'` was less than the standard pool entry timeserial `'t:0'` (since `'9' < 't'` in string ordering), causing the operation to be rejected as stale.
+
+**Test**: Adapted to use serial `'t:1'` which sorts after `'t:0'`.
+
+---
+
 ## Mock Infrastructure Limitations
 
 ### MsgPack encoding/decoding not supported

test/uts/mock_websocket.ts

@@ -19,6 +19,8 @@ const DEFAULT_CONNECTED = {
     maxIdleInterval: 15000,
     maxMessageSize: 65536,
     serverId: 'test-server',
+    siteCode: 'test',
+    objectsGCGracePeriod: 86400000,
   },
   error: null as any,
 };