test: cover zone content kind lock and sequence groups

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_sequence_zone_groups.py

@@ -0,0 +1,28 @@
+"""Sequence playback targets only explicitly checked lane groups."""
+
+from util.sequence_playback import (
+    _group_ids_for_lane_step,
+    _partition_devices_for_lane,
+    _resolve_step_device_names,
+    _split_device_names_for_lane,
+)
+
+
+def test_empty_lane_groups_do_not_default_to_zone():
+    zone = {"group_ids": ["g1", "g2"]}
+    seq = {"lanes": [[{"preset_id": "1", "beats": 1}]], "lanes_group_ids": [[]]}
+    gids = _group_ids_for_lane_step(seq, seq["lanes"][0][0], 0, 1, zone_doc=zone)
+    assert gids == []
+
+
+def test_resolve_step_with_no_groups_returns_empty():
+    zone = {"group_ids": ["g1"], "names": ["dev-a"]}
+    names = _resolve_step_device_names(zone, [], None, None)
+    assert names == []
+
+
+def test_whole_zone_not_partitioned_across_lanes():
+    names = ["dev-a", "dev-b", "dev-c"]
+    assert _split_device_names_for_lane(names, 0, 2, partition_shared_zone=False) == names
+    assert _split_device_names_for_lane(names, 1, 2, partition_shared_zone=False) == names
+    assert not _partition_devices_for_lane(2, lane_has_own_groups=False, step_group_ids=[])