fix fast tests

tests/mocks/mock_motors_bus.py

@@ -17,6 +17,7 @@
 from lerobot.motors.motors_bus import (
     Motor,
     MotorsBus,
+    MotorsBusBase,
 )
 
 DUMMY_CTRL_TABLE_1 = {
@@ -122,6 +123,12 @@ class MockPortHandler:
 
 
 class MockMotorsBus(MotorsBus):
+    """Mock motor bus that bypasses hardware dependency checks.
+
+    Inherits from MotorsBus (alias for SerialMotorsBus) for type compatibility,
+    but calls MotorsBusBase.__init__ directly to skip the pyserial/deepdiff guards.
+    """
+
     available_baudrates = [500_000, 1_000_000]
     default_timeout = 1000
     model_baudrate_table = DUMMY_MODEL_BAUDRATE_TABLE
@@ -132,8 +139,13 @@ class MockMotorsBus(MotorsBus):
     normalized_data = ["Present_Position", "Goal_Position"]
 
     def __init__(self, port: str, motors: dict[str, Motor]):
-        super().__init__(port, motors)
+        # Skip SerialMotorsBus.__init__ (which guards pyserial/deepdiff)
+        # and call the base class directly — this mock never touches real serial.
+        MotorsBusBase.__init__(self, port, motors)
         self.port_handler = MockPortHandler(port)
+        self._id_to_model_dict = {m.id: m.model for m in self.motors.values()}
+        self._id_to_name_dict = {m.id: name for name, m in self.motors.items()}
+        self._model_nb_to_model_dict = {v: k for k, v in self.model_number_table.items()}
 
     def _assert_protocol_is_compatible(self, instruction_name): ...
     def _handshake(self): ...

tests/test_control_robot.py

@@ -19,6 +19,7 @@ from unittest.mock import patch
 import pytest
 
 pytest.importorskip("datasets", reason="datasets is required (install lerobot[dataset])")
+pytest.importorskip("deepdiff", reason="deepdiff is required (install lerobot[hardware])")
 
 from lerobot.scripts.lerobot_calibrate import CalibrateConfig, calibrate
 from lerobot.scripts.lerobot_record import DatasetRecordConfig, RecordConfig, record