AMI430 3D driver: add docstring, extra test for initializing from AMI430 by name

qcodes/instrument_drivers/american_magnetics/AMI430.py

@@ -469,6 +469,26 @@ def __init__(self,
                  field_limit: Union[numbers.Real,
                                     Iterable[CartesianFieldLimitFunction]],
                  **kwargs: Any):
+        """
+        Driver for controlling three American Magnetics Model 430 magnet power
+        supplies simultaneously for setting magnetic field vectors.
+
+        The individual magnet power supplies can be passed in as either
+        instances of AMI430 driver or as names of existing AMI430 instances.
+        In the latter case, the instances will be found via the passed names.
+
+        Args:
+            name: a name for the instrument
+            instrument_x: AMI430 instance or a names of existing AMI430
+                instance for controlling the X axis of magnetic field
+            instrument_y: AMI430 instance or a names of existing AMI430
+                instance for controlling the X axis of magnetic field
+            instrument_z: AMI430 instance or a names of existing AMI430
+                instance for controlling the X axis of magnetic field
+            field_limit: a number for maximum allows magnetic field or an
+                iterable of callable field limit functions that define
+                region(s) of allowed values in 3D magnetic field space
+        """
         super().__init__(name, **kwargs)
 
         if not isinstance(name, str):

qcodes/tests/drivers/test_ami430.py

@@ -11,8 +11,10 @@
 from hypothesis.strategies import floats, tuples
 
 import qcodes.instrument.sims as sims
+from qcodes.instrument.base import Instrument
 from qcodes.instrument.ip_to_visa import AMI430_VISA
-from qcodes.instrument_drivers.american_magnetics.AMI430 import (AMI430_3D,
+from qcodes.instrument_drivers.american_magnetics.AMI430 import (AMI430,
+                                                                 AMI430_3D,
                                                                  AMI430Warning)
 from qcodes.math_utils.field_vector import FieldVector
 from qcodes.utils.types import (numpy_concrete_floats, numpy_concrete_ints,
@@ -124,7 +126,7 @@ def test_instantiation_from_names(magnet_axes_instances, request):
     assert driver._instrument_z is mag_z
 
 
-def test_instantiation_from_name_of_nonexistent_instrument(
+def test_instantiation_from_name_of_nonexistent_ami_instrument(
         magnet_axes_instances, request
 ):
     mag_x, mag_y, mag_z = magnet_axes_instances
@@ -143,6 +145,29 @@ def test_instantiation_from_name_of_nonexistent_instrument(
         )
 
 
+def test_instantiation_from_name_of_existing_non_ami_instrument(
+        magnet_axes_instances, request
+):
+    mag_x, mag_y, mag_z = magnet_axes_instances
+    request.addfinalizer(AMI430_3D.close_all)
+
+    non_ami_existing_instrument = Instrument("foo")
+
+    with pytest.raises(
+            TypeError,
+            match=re.escape(
+                f"Instrument {non_ami_existing_instrument.name} is "
+                f"{type(non_ami_existing_instrument)} but {AMI430} "
+                f"was requested"
+            )
+    ):
+        AMI430_3D(
+            "AMI430-3D",
+            mag_x.name, non_ami_existing_instrument.name, mag_z.name,
+            field_limit
+        )
+
+
 def test_instantiation_from_badly_typed_argument(
         magnet_axes_instances, request
 ):