fix(api): skip transfers if volume is zero, improve error when out of tips

api/src/opentrons/protocol_api/core/engine/instrument.py

@@ -1238,7 +1238,8 @@ def _pick_up_tip() -> WellCore:
             )
             if next_tip is None:
                 raise RuntimeError(
-                    f"No tip available among {tip_racks} for this transfer."
+                    f"No tip available among the tipracks assigned for {self.get_pipette_name()}:"
+                    f" {[f'{tip_rack[1].get_display_name()} in {tip_rack[1].get_deck_slot()}' for tip_rack in tip_racks]}"
                 )
             (
                 tiprack_loc,
@@ -1478,7 +1479,8 @@ def _pick_up_tip() -> WellCore:
             )
             if next_tip is None:
                 raise RuntimeError(
-                    f"No tip available among {tip_racks} for this transfer."
+                    f"No tip available among the tipracks assigned for {self.get_pipette_name()}:"
+                    f" {[f'{tip_rack[1].get_display_name()} in {tip_rack[1].get_deck_slot()}' for tip_rack in tip_racks]}"
                 )
             (
                 tiprack_loc,
@@ -1569,7 +1571,7 @@ def _pick_up_tip() -> WellCore:
                 and not transfer_props.multi_dispense.retract.blowout.enabled
             ):
                 raise RuntimeError(
-                    "Distribute liquid uses a disposal volume but location for disposing of"
+                    "Distribute uses a disposal volume but location for disposing of"
                     " the disposal volume cannot be found when blowout is disabled."
                     " Specify a blowout location and enable blowout when using a disposal volume."
                 )
@@ -1751,7 +1753,8 @@ def _pick_up_tip() -> WellCore:
             )
             if next_tip is None:
                 raise RuntimeError(
-                    f"No tip available among {tip_racks} for this transfer."
+                    f"No tip available among the tipracks assigned for {self.get_pipette_name()}:"
+                    f" {[ f'{tip_rack[1].get_display_name()} in {tip_rack[1].get_deck_slot()}' for tip_rack in tip_racks]}"
                 )
             (
                 tiprack_loc,

api/src/opentrons/protocol_api/instrument_context.py

@@ -1553,6 +1553,13 @@ def transfer_with_liquid_class(
         :param return_tip: Whether to drop used tips in their original locations
             in the tip rack, instead of the trash.
         """
+        if volume == 0.0:
+            _log.info(
+                f"Transfer of {liquid_class.name} specified with a volume of 0uL."
+                f" Skipping."
+            )
+            return self
+
         transfer_args = verify_and_normalize_transfer_args(
             source=source,
             dest=dest,
@@ -1645,6 +1652,13 @@ def distribute_with_liquid_class(
         :param return_tip: Whether to drop used tips in their original locations
             in the tip rack, instead of the trash.
         """
+        if volume == 0.0:
+            _log.info(
+                f"Distribution of {liquid_class.name} specified with a volume of 0uL."
+                f" Skipping."
+            )
+            return self
+
         transfer_args = verify_and_normalize_transfer_args(
             source=source,
             dest=dest,
@@ -1743,6 +1757,13 @@ def consolidate_with_liquid_class(
         :param return_tip: Whether to drop used tips in their original locations
             in the tip rack, instead of the trash.
         """
+        if volume == 0.0:
+            _log.info(
+                f"Consolidation of {liquid_class.name} specified with a volume of 0uL."
+                f" Skipping."
+            )
+            return self
+
         transfer_args = verify_and_normalize_transfer_args(
             source=source,
             dest=dest,

api/tests/opentrons/protocol_api_integration/test_transfer_with_liquid_classes.py

@@ -2063,3 +2063,61 @@ def test_water_transfer_with_multi_channel_pipette(
         )
         assert patched_aspirate.call_count == 2
         assert patched_dispense.call_count == 2
+
+
+@pytest.mark.ot3_only
+@pytest.mark.parametrize(
+    "simulated_protocol_context", [("2.23", "Flex")], indirect=True
+)
+def test_raises_no_tips_available_error(
+    simulated_protocol_context: ProtocolContext,
+) -> None:
+    """It should raise an error explaining that there aren't any tips available."""
+    trash = simulated_protocol_context.load_trash_bin("A3")
+    tiprack1 = simulated_protocol_context.load_labware(
+        "opentrons_flex_96_tiprack_50ul", "D1"
+    )
+    tiprack2 = simulated_protocol_context.load_labware(
+        "opentrons_flex_96_tiprack_50ul", "D2"
+    )
+    pipette_50 = simulated_protocol_context.load_instrument(
+        "flex_1channel_50", mount="left", tip_racks=[tiprack1, tiprack2]
+    )
+    nest_plate = simulated_protocol_context.load_labware(
+        "nest_96_wellplate_200ul_flat", "C3"
+    )
+    arma_plate = simulated_protocol_context.load_labware(
+        "armadillo_96_wellplate_200ul_pcr_full_skirt", "C2"
+    )
+    water = simulated_protocol_context.define_liquid_class("water")
+    expected_error_msg = (
+        "No tip available among the tipracks assigned for flex_1channel_50:"
+        " \\['Opentrons Flex 96 Tip Rack 50 µL in D1', 'Opentrons Flex 96 Tip Rack 50 µL in D2'\\]"
+    )
+    with pytest.raises(RuntimeError, match=expected_error_msg):
+        pipette_50.transfer_with_liquid_class(
+            liquid_class=water,
+            volume=160,
+            source=nest_plate.columns(),
+            dest=arma_plate.columns(),
+            new_tip="always",
+            trash_location=trash,
+        )
+    with pytest.raises(RuntimeError, match=f"{expected_error_msg}"):
+        pipette_50.distribute_with_liquid_class(
+            liquid_class=water,
+            volume=160,
+            source=nest_plate.wells()[-1],
+            dest=arma_plate.columns(),
+            new_tip="once",
+            trash_location=trash,
+        )
+    with pytest.raises(RuntimeError, match=f"{expected_error_msg}"):
+        pipette_50.consolidate_with_liquid_class(
+            liquid_class=water,
+            volume=50,
+            source=nest_plate.columns(),
+            dest=arma_plate.wells()[0],
+            new_tip="once",
+            trash_location=trash,
+        )