From ea31e34e0076341690e71a41167e98d32ea3d7ef Mon Sep 17 00:00:00 2001
From: aaron-kulkarni <107003644+aaron-kulkarni@users.noreply.github.com>
Date: Tue, 23 Jul 2024 14:32:39 -0400
Subject: [PATCH] fix(api): throw error if no valid nozzle has tip (#15721)

Provide a check in all LLD functions(called manually or automatically
during aspirate) that makes sure that if it's a 96-channel pipette, that
at least one of the nozzles with a pressure sensor has a tip on it.

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---
 .../protocol_api/instrument_context.py        | 19 ++++++
 .../protocol_api/test_instrument_context.py   | 59 +++++++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/api/src/opentrons/protocol_api/instrument_context.py b/api/src/opentrons/protocol_api/instrument_context.py
index 05a8ecdc80c..c39a4aba2ac 100644
--- a/api/src/opentrons/protocol_api/instrument_context.py
+++ b/api/src/opentrons/protocol_api/instrument_context.py
@@ -2,6 +2,7 @@
 import logging
 from contextlib import ExitStack
 from typing import Any, List, Optional, Sequence, Union, cast, Dict
+from opentrons.protocol_engine.errors.exceptions import TipNotAttachedError
 from opentrons_shared_data.errors.exceptions import (
     CommandPreconditionViolated,
     CommandParameterLimitViolated,
@@ -264,6 +265,7 @@ def aspirate(
             self.api_version >= APIVersion(2, 20)
             and well is not None
             and self.liquid_presence_detection
+            and self._96_tip_config_valid()
         ):
             self.require_liquid_presence(well=well)
             self.prepare_to_aspirate()
@@ -1874,6 +1876,19 @@ def _get_last_location_by_api_version(self) -> Optional[types.Location]:
         else:
             return self._protocol_core.get_last_location()
 
+    def _96_tip_config_valid(self) -> bool:
+        n_map = self._core.get_nozzle_map()
+        channels = self._core.get_active_channels()
+        if channels == 96:
+            if (
+                n_map.back_left != n_map.full_instrument_back_left
+                and n_map.front_right != n_map.full_instrument_front_right
+            ):
+                raise TipNotAttachedError(
+                    "Either the front right or the back left nozzle must have a tip attached to do LLD."
+                )
+        return True
+
     def __repr__(self) -> str:
         return "<{}: {} in {}>".format(
             self.__class__.__name__,
@@ -2110,6 +2125,7 @@ def detect_liquid_presence(self, well: labware.Well) -> bool:
         :returns: A boolean.
         """
         loc = well.top()
+        self._96_tip_config_valid()
         return self._core.detect_liquid_presence(well._core, loc)
 
     @requires_version(2, 20)
@@ -2119,6 +2135,7 @@ def require_liquid_presence(self, well: labware.Well) -> None:
         :returns: None.
         """
         loc = well.top()
+        self._96_tip_config_valid()
         self._core.liquid_probe_with_recovery(well._core, loc)
 
     @requires_version(2, 20)
@@ -2131,6 +2148,8 @@ def measure_liquid_height(self, well: labware.Well) -> float:
 
         This is intended for Opentrons internal use only and is not a guaranteed API.
         """
+
         loc = well.top()
+        self._96_tip_config_valid()
         height = self._core.liquid_probe_without_recovery(well._core, loc)
         return height
diff --git a/api/tests/opentrons/protocol_api/test_instrument_context.py b/api/tests/opentrons/protocol_api/test_instrument_context.py
index d98b99a9a6d..0e85082c3e2 100644
--- a/api/tests/opentrons/protocol_api/test_instrument_context.py
+++ b/api/tests/opentrons/protocol_api/test_instrument_context.py
@@ -17,6 +17,12 @@
 
 from opentrons.legacy_broker import LegacyBroker
 
+from opentrons.protocol_engine.errors.exceptions import TipNotAttachedError
+from tests.opentrons.protocol_engine.pipette_fixtures import (
+    NINETY_SIX_COLS,
+    NINETY_SIX_MAP,
+    NINETY_SIX_ROWS,
+)
 from opentrons.protocols.api_support import instrument as mock_instrument_support
 from opentrons.protocols.api_support.types import APIVersion
 from opentrons.protocols.api_support.util import (
@@ -1351,3 +1357,56 @@ def test_measure_liquid_height(
     with pytest.raises(ProtocolCommandFailedError) as pcfe:
         subject.measure_liquid_height(mock_well)
     assert pcfe.value is errorToRaise
+
+
+def test_96_tip_config_valid(
+    decoy: Decoy, mock_instrument_core: InstrumentCore, subject: InstrumentContext
+) -> None:
+    """It should error when there's no tips on the correct corner nozzles."""
+    nozzle_map = NozzleMap.build(
+        physical_nozzles=NINETY_SIX_MAP,
+        physical_rows=NINETY_SIX_ROWS,
+        physical_columns=NINETY_SIX_COLS,
+        starting_nozzle="A5",
+        back_left_nozzle="A5",
+        front_right_nozzle="H5",
+        valid_nozzle_maps=ValidNozzleMaps(maps={"Column12": NINETY_SIX_COLS["5"]}),
+    )
+    decoy.when(mock_instrument_core.get_nozzle_map()).then_return(nozzle_map)
+    decoy.when(mock_instrument_core.get_active_channels()).then_return(96)
+    with pytest.raises(TipNotAttachedError):
+        subject._96_tip_config_valid()
+
+
+def test_96_tip_config_invalid(
+    decoy: Decoy, mock_instrument_core: InstrumentCore, subject: InstrumentContext
+) -> None:
+    """It should return True when there are tips on the correct corner nozzles."""
+    nozzle_map = NozzleMap.build(
+        physical_nozzles=NINETY_SIX_MAP,
+        physical_rows=NINETY_SIX_ROWS,
+        physical_columns=NINETY_SIX_COLS,
+        starting_nozzle="A1",
+        back_left_nozzle="A1",
+        front_right_nozzle="H12",
+        valid_nozzle_maps=ValidNozzleMaps(
+            maps={
+                "Full": sum(
+                    [
+                        NINETY_SIX_ROWS["A"],
+                        NINETY_SIX_ROWS["B"],
+                        NINETY_SIX_ROWS["C"],
+                        NINETY_SIX_ROWS["D"],
+                        NINETY_SIX_ROWS["E"],
+                        NINETY_SIX_ROWS["F"],
+                        NINETY_SIX_ROWS["G"],
+                        NINETY_SIX_ROWS["H"],
+                    ],
+                    [],
+                )
+            }
+        ),
+    )
+    decoy.when(mock_instrument_core.get_nozzle_map()).then_return(nozzle_map)
+    decoy.when(mock_instrument_core.get_active_channels()).then_return(96)
+    assert subject._96_tip_config_valid() is True