From bd7f541d586de0a3d571bbbce6bee2d29baeb4c7 Mon Sep 17 00:00:00 2001
From: Jeremy Leon <jeremy.leon@opentrons.com>
Date: Thu, 7 Sep 2023 09:46:12 -0400
Subject: [PATCH] fix(engine): fix labware gripperOffsets not allowing only a
 default offset (#13472)

---
 .../protocol_engine/state/labware.py          | 10 ++---
 .../state/test_labware_view.py                | 45 +++++++++++++++++++
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/api/src/opentrons/protocol_engine/state/labware.py b/api/src/opentrons/protocol_engine/state/labware.py
index 80d2c2b6725..80d8a3b6b09 100644
--- a/api/src/opentrons/protocol_engine/state/labware.py
+++ b/api/src/opentrons/protocol_engine/state/labware.py
@@ -751,8 +751,11 @@ def get_labware_gripper_offsets(
         """Get the labware's gripper offsets of the specified type."""
         parsed_offsets = self.get_definition(labware_id).gripperOffsets
         offset_key = slot_name.name if slot_name else "default"
-        return (
-            LabwareMovementOffsetData(
+
+        if parsed_offsets is None or offset_key not in parsed_offsets:
+            return None
+        else:
+            return LabwareMovementOffsetData(
                 pickUpOffset=cast(
                     LabwareOffsetVector, parsed_offsets[offset_key].pickUpOffset
                 ),
@@ -760,9 +763,6 @@ def get_labware_gripper_offsets(
                     LabwareOffsetVector, parsed_offsets[offset_key].dropOffset
                 ),
             )
-            if parsed_offsets
-            else None
-        )
 
     def get_grip_force(self, labware_id: str) -> float:
         """Get the recommended grip force for gripping labware using gripper."""
diff --git a/api/tests/opentrons/protocol_engine/state/test_labware_view.py b/api/tests/opentrons/protocol_engine/state/test_labware_view.py
index 535c2c68694..7d277d93b5a 100644
--- a/api/tests/opentrons/protocol_engine/state/test_labware_view.py
+++ b/api/tests/opentrons/protocol_engine/state/test_labware_view.py
@@ -10,6 +10,8 @@
     Parameters,
     LabwareRole,
     OverlapOffset as SharedDataOverlapOffset,
+    GripperOffsets,
+    OffsetVector,
 )
 from opentrons.protocols.models import LabwareDefinition
 from opentrons.types import DeckSlotName, Point, MountType
@@ -1346,6 +1348,49 @@ def test_get_labware_gripper_offsets(
     )
 
 
+def test_get_labware_gripper_offsets_default_no_slots(
+    well_plate_def: LabwareDefinition,
+    adapter_plate_def: LabwareDefinition,
+) -> None:
+    """It should get the labware's gripper offsets with only a default gripper offset entry."""
+    subject = get_labware_view(
+        labware_by_id={
+            "labware-id": LoadedLabware(
+                id="labware-id",
+                loadName="labware-load-name",
+                location=DeckSlotLocation(slotName=DeckSlotName.SLOT_1),
+                definitionUri="some-labware-uri",
+                offsetId=None,
+                displayName="Fancy Labware Name",
+            )
+        },
+        definitions_by_uri={
+            "some-labware-uri": LabwareDefinition.construct(  # type: ignore[call-arg]
+                gripperOffsets={
+                    "default": GripperOffsets(
+                        pickUpOffset=OffsetVector(x=1, y=2, z=3),
+                        dropOffset=OffsetVector(x=4, y=5, z=6),
+                    )
+                }
+            ),
+        },
+    )
+
+    assert (
+        subject.get_labware_gripper_offsets(
+            labware_id="labware-id", slot_name=DeckSlotName.SLOT_D1
+        )
+        is None
+    )
+
+    assert subject.get_labware_gripper_offsets(
+        labware_id="labware-id", slot_name=None
+    ) == LabwareMovementOffsetData(
+        pickUpOffset=LabwareOffsetVector(x=1, y=2, z=3),
+        dropOffset=LabwareOffsetVector(x=4, y=5, z=6),
+    )
+
+
 def test_get_grip_force(
     flex_50uL_tiprack: LabwareDefinition,
     reservoir_def: LabwareDefinition,