rack：fan 命令放行保持时间 sec，风扇断电显示「停」

Co-Authored-By: Claude Opus 5.5 <[email protected]>

rack/backend/tests/test_core.py

@@ -59,12 +59,24 @@ def test_build_command_whitelist_and_ranges():
         {"cmd": "power", "rail": True, "on": True},         # bool 不是 int
         {"cmd": "vbus", "rail": 1, "on": 1},
         {"cmd": "fan", "duty": 1001},
+        {"cmd": "fan", "duty": 500, "sec": 86401},
+        {"cmd": "fan", "duty": 500, "sec": -1},
+        {"cmd": "fan", "duty": 500, "sec": "60"},
+        {"cmd": "fan", "duty": 500, "sec": True},
     ]
     for b in bad:
         with pytest.raises(protocol.CmdError):
             protocol.build_command(b)
 
 
+def test_fan_floor_may_carry_a_hold_time():
+    """固件 0.1.21：`sec` 原样带下去；0 / 不给 = 一直保持，命令里就不出现这个键（老固件不认它也没关系）。"""
+    assert protocol.build_command({"cmd": "fan", "duty": 600}) == {"cmd": "fan", "duty": 600}
+    assert protocol.build_command({"cmd": "fan", "duty": 600, "sec": 0}) == {"cmd": "fan", "duty": 600}
+    assert protocol.build_command({"cmd": "fan", "duty": 600, "sec": 90}) == {"cmd": "fan", "duty": 600, "sec": 90}
+    assert protocol.build_command({"cmd": "fan", "duty": 0, "sec": 86400}) == {"cmd": "fan", "duty": 0, "sec": 86400}
+
+
 def test_seq_is_strictly_increasing_and_in_range():
     t = [1700000000.0]
     g = protocol.SeqGen(clock=lambda: t[0])