Improve InstrumentRef parameter

src/qcodes/instrument/channel.py

@@ -26,6 +26,7 @@
 
     from typing_extensions import Unpack
 
+    from .instrument import Instrument
     from .instrument_base import InstrumentBaseKWArgs
 
 
@@ -86,8 +87,14 @@ def parent(self) -> _TIB_co:
         return self._parent
 
     @property
-    def root_instrument(self) -> InstrumentBase:
-        return self._parent.root_instrument
+    def root_instrument(self) -> Instrument:
+        # the root instrument is the top level parent of this module, we need to
+        # go up the parent hierarchy until we find an object that returns itself as the parent, this should be the root instrument. We also
+        # this is required to be an Instrument.
+        # Once 3.13 is the minimum supported version
+        # consider replacing with a generic parameter with a default
+        # value of Instrument.
+        return cast("Instrument", self._parent.root_instrument)
 
     @property
     def name_parts(self) -> list[str]:

src/qcodes/instrument/instrument_base.py

@@ -18,7 +18,7 @@
 
 if TYPE_CHECKING:
     from collections.abc import Callable, Mapping, Sequence
-    from typing import NotRequired
+    from typing import NotRequired, Self
 
     from qcodes.instrument.channel import ChannelTuple, InstrumentModule
     from qcodes.logger.instrument_logger import InstrumentLoggerAdapter
@@ -579,7 +579,7 @@ def ancestors(self) -> tuple[InstrumentBase, ...]:
             return (self,)
 
     @property
-    def root_instrument(self) -> InstrumentBase:
+    def root_instrument(self) -> Self:
         """
         The topmost parent of this module.
 

src/qcodes/parameters/parameter_base.py

@@ -8,7 +8,7 @@
 from contextlib import contextmanager
 from datetime import datetime
 from functools import cached_property, wraps
-from typing import TYPE_CHECKING, Any, ClassVar, Generic, overload
+from typing import TYPE_CHECKING, Any, ClassVar, Generic, cast, overload
 
 import numpy as np
 from typing_extensions import TypeVar
@@ -47,7 +47,7 @@
     from types import TracebackType
 
     from qcodes.dataset.data_set_protocol import ValuesType
-    from qcodes.instrument import InstrumentBase
+    from qcodes.instrument import Instrument, InstrumentBase
     from qcodes.logger.instrument_logger import InstrumentLoggerAdapter
 ParameterDataTypeVar = TypeVar("ParameterDataTypeVar", default=Any)
 # InstrumentTypeVar_co is a covariant type variable representing the instrument
@@ -1209,15 +1209,15 @@ def instrument(self) -> InstrumentTypeVar_co:
         return self._instrument
 
     @property
-    def root_instrument(self) -> InstrumentBase | None:
+    def root_instrument(self) -> Instrument | None:
         """
         Return the fundamental instrument that this parameter belongs too.
         E.g if the parameter is bound to a channel this will return the
         fundamental instrument that that channel belongs to. Use
         :meth:`instrument` to get the channel.
         """
         if self._instrument is not None:
-            return self._instrument.root_instrument
+            return cast("Instrument | None", self._instrument.root_instrument)
         else:
             return None
 

src/qcodes/parameters/specialized_parameters.py

@@ -8,8 +8,9 @@
 
 import warnings
 from time import perf_counter
-from typing import TYPE_CHECKING, Any, ClassVar, Literal
+from typing import TYPE_CHECKING, Any, ClassVar, Generic, Literal
 
+from qcodes.parameters.parameter_base import InstrumentTypeVar_co
 from qcodes.utils import QCoDeSDeprecationWarning
 from qcodes.validators import Strings, Validator
 
@@ -18,7 +19,7 @@
 if TYPE_CHECKING:
     from collections.abc import Callable
 
-    from qcodes.instrument import InstrumentBase
+    from qcodes.instrument import Instrument
 
 
 class ElapsedTimeParameter(Parameter):
@@ -96,7 +97,9 @@ def t0(self) -> float:
         return self._t0
 
 
-class InstrumentRefParameter(Parameter):
+class InstrumentRefParameter(
+    Parameter[str, InstrumentTypeVar_co], Generic[InstrumentTypeVar_co]
+):
     """
     An instrument reference parameter.
 
@@ -134,12 +137,12 @@ def __init__(
         self,
         name: str,
         *args: Any,
-        instrument: InstrumentBase | None = None,
+        instrument: InstrumentTypeVar_co = None,
         label: str | None = None,
         unit: str | None = None,
         get_cmd: str | Callable[..., Any] | Literal[False] | None = None,
         set_cmd: str | Callable[..., Any] | Literal[False] | None = None,
-        initial_value: float | str | None = None,
+        initial_value: str | None = None,
         max_val_age: float | None = None,
         vals: Validator[Any] | None = None,
         docstring: str | None = None,
@@ -229,16 +232,15 @@ def __init__(
             **kwargs,
         )
 
-    # TODO(nulinspiratie) check class works now it's subclassed from Parameter
-    def get_instr(self) -> InstrumentBase:
+    def get_instr(self) -> Instrument | None:
         """
         Returns the instance of the instrument with the name equal to the
         value of this parameter.
         """
+        # lazy import to avoid circular import
+        # since Instrument module depends on parameer module
+        from qcodes.instrument import Instrument  # noqa: PLC0415
+
         ref_instrument_name = self.get()
-        # note that _instrument refers to the instrument this parameter belongs
-        # to, while the ref_instrument_name is the instrument that is the value
-        # of this parameter.
-        if self._instrument is None:
-            raise RuntimeError("InstrumentRefParameter is not bound to an instrument.")
-        return self._instrument.find_instrument(ref_instrument_name)
+
+        return Instrument.find_instrument(ref_instrument_name)

tests/drivers/keysight_b1500/b1500_driver_tests/test_b1517a_smu.py

@@ -433,7 +433,7 @@ def test_iv_sweep_delay(smu: KeysightB1517A) -> None:
     smu.iv_sweep.step_delay(0.01)
     smu.iv_sweep.trigger_delay(0.1)
     smu.iv_sweep.measure_delay(15.4)
-
+    assert isinstance(mainframe, MagicMock)
     mainframe.write.assert_has_calls(
         [
             call("WT 43.12,0.0,0.0,0.0,0.0"),

tests/drivers/keysight_b1500/b1500_driver_tests/test_b1520a_cmu.py

@@ -179,7 +179,7 @@ def test_get_post_sweep_voltage_cond(cmu: KeysightB1520A) -> None:
 
 def test_cv_sweep_delay(cmu: KeysightB1520A) -> None:
     mainframe = cmu.root_instrument
-
+    assert isinstance(mainframe, MagicMock)
     mainframe.ask.return_value = "WTDCV0.0,0.0,0.0,0.0,0.0"
 
     cmu.cv_sweep.hold_time(1.0)
@@ -192,6 +192,7 @@ def test_cv_sweep_delay(cmu: KeysightB1520A) -> None:
 
 def test_cmu_sweep_steps(cmu: KeysightB1520A) -> None:
     mainframe = cmu.root_instrument
+    assert isinstance(mainframe, MagicMock)
     mainframe.ask.return_value = "WDCV3,1,0.0,0.0,1"
     cmu.cv_sweep.sweep_start(2.0)
     cmu.cv_sweep.sweep_end(4.0)
@@ -208,6 +209,7 @@ def test_cv_sweep_voltages(cmu: KeysightB1520A) -> None:
     end = 1.0
     steps = 5
     return_string = f"WDCV3,1,{start},{end},{steps}"
+    assert isinstance(mainframe, MagicMock)
     mainframe.ask.return_value = return_string
 
     cmu.cv_sweep.sweep_start(start)
@@ -226,6 +228,7 @@ def test_sweep_modes(cmu: KeysightB1520A) -> None:
     steps = 5
     mode = constants.SweepMode.LINEAR_TWO_WAY
     return_string = f"WDCV3,{mode},{start},{end},{steps}"
+    assert isinstance(mainframe, MagicMock)
     mainframe.ask.return_value = return_string
 
     cmu.cv_sweep.sweep_start(start)
@@ -249,6 +252,7 @@ def test_run_sweep(cmu: KeysightB1520A) -> None:
         f"0.0000;WDCV3,"
         f"1,{start},{end},{steps};ACT0,1"
     )
+    assert isinstance(mainframe, MagicMock)
     mainframe.ask.return_value = return_string
     cmu.setup_fnc_already_run = True
     cmu.impedance_model(constants.IMP.MeasurementMode.G_X)

tests/drivers/keysight_b1500/b1500_driver_tests/test_sampling_measurement.py

@@ -83,6 +83,7 @@ def test_sampling_measurement(
     actual_data = smu.sampling_measurement_trace.get()
 
     np.testing.assert_allclose(actual_data, data_to_return, atol=1e-3)
+    assert isinstance(smu.root_instrument.ask, Mock)
     smu.root_instrument.ask.assert_called_with("XE")
 
 

tests/parameter/test_instrument_ref_parameter.py

@@ -9,28 +9,32 @@
     from collections.abc import Generator
 
 
+class DummyHolder(DummyInstrument):
+    def __init__(self, name: str) -> None:
+        super().__init__(name)
+        self.test = self.add_parameter(
+            "test",
+            parameter_class=InstrumentRefParameter,
+            initial_value=None,
+        )
+
+
 @pytest.fixture(name="instrument_a")
-def _make_instrument_a() -> "Generator[DummyInstrument, None, None]":
-    a = DummyInstrument("dummy_holder")
-    try:
-        yield a
-    finally:
-        a.close()
+def _make_instrument_a() -> "Generator[DummyHolder, None, None]":
+
+    a = DummyHolder("dummy_holder")
+    yield a
+    a.close()
 
 
 @pytest.fixture(name="instrument_d")
 def _make_instrument_d() -> "Generator[DummyInstrument, None, None]":
     d = DummyInstrument("dummy")
-    try:
-        yield d
-    finally:
-        d.close()
+    yield d
+    d.close()
 
 
-def test_get_instr(
-    instrument_a: DummyInstrument, instrument_d: DummyInstrument
-) -> None:
-    instrument_a.add_parameter("test", parameter_class=InstrumentRefParameter)
+def test_get_instr(instrument_a: DummyHolder, instrument_d: DummyInstrument) -> None:
 
     instrument_a.test.set(instrument_d.name)