better error messages and tests for new ones

Author: sfoster1

api/src/opentrons/protocol_api/labware.py

@@ -1166,7 +1166,11 @@ def load_liquid(
                 well_names.append(well.well_name)
             else:
                 raise TypeError(
-                    "The elements of wells should be Well instances or well names."
+                    f"Unexpected type for element {repr(well)}. The elements of wells should be Well instances or well names."
+                )
+            if not isinstance(volume, (float, int)):
+                raise TypeError(
+                    f"Unexpected type for volume {repr(volume)}. Volume should be a number in microliters."
                 )
         self._core.load_liquid({well_name: volume for well_name in well_names}, liquid)
 
@@ -1211,7 +1215,11 @@ def load_liquid_by_well(
                 verified_volumes[well.well_name] = volume
             else:
                 raise TypeError(
-                    "The elements of wells should be Well instances or well names."
+                    f"Unexpected type for well name {repr(well)}. The keys of volumes should be Well instances or well names."
+                )
+            if not isinstance(volume, (float, int)):
+                raise TypeError(
+                    f"Unexpected type for volume {repr(volume)}. The values of volumes should be numbers in microliters."
                 )
         self._core.load_liquid(verified_volumes, liquid)
 
@@ -1235,18 +1243,18 @@ def load_empty(self, wells: Sequence[Union[Well, str]]) -> None:
             if isinstance(well, str):
                 if well not in self:
                     raise KeyError(
-                        "The elements of wells should name wells in this labware."
+                        f"{well} is not a well in {self.name}. The elements of wells should name wells in this labware."
                     )
                 well_names.append(well)
             elif isinstance(well, Well):
                 if well.parent is not self:
                     raise KeyError(
-                        "The elements of wells should be wells of this labware."
+                        f"{well.well_name} is not a well in {self.name}. The elements of wells should be wells of this labware."
                     )
                 well_names.append(well.well_name)
             else:
                 raise TypeError(
-                    "The elements of wells should be Well instances or well names."
+                    f"Unexpected type for well name {repr(well)}. The elements of wells should be Well instances or well names."
                 )
         self._core.load_empty(well_names)
 

api/tests/opentrons/protocol_api/test_labware.py

@@ -467,6 +467,8 @@ def test_load_liquid_rejects_invalid_inputs(
     with pytest.raises(TypeError):
         subject.load_liquid([2], 10, mock_liquid)  # type: ignore[list-item]
 
+    with pytest.raises(TypeError):
+        subject.load_liquid(["A1"], "A1", mock_liquid)  # type: ignore[arg-type]
     mock_liquid = decoy.mock(cls=Liquid)
 
     subject.load_liquid(["A1", subject["B1"]], 10, mock_liquid)
@@ -587,6 +589,9 @@ def test_load_liquid_by_well_rejects_invalid_inputs(
     with pytest.raises(TypeError):
         subject.load_liquid_by_well({2: 10}, mock_liquid)  # type: ignore[dict-item]
 
+    with pytest.raises(TypeError):
+        subject.load_liquid_by_well({"A1": "A3"}, mock_liquid)  # type: ignore[dict-item]
+
 
 @pytest.mark.parametrize("api_version", versions_at_or_above(APIVersion(2, 22)))
 def test_load_empty_handles_valid_inputs(