fix(resources): make TipTracker.get_tip use pending state

pylabrobot/legacy/liquid_handling/backends/hamilton/STAR_backend.py

@@ -1473,8 +1473,7 @@ async def pick_up_tips(
 
     x_positions, y_positions, channels_involved = self._ops_to_fw_positions(ops, use_channels)
 
-    tip_spots = [op.resource for op in ops]
-    tips = set(cast(HamiltonTip, tip_spot.get_tip()) for tip_spot in tip_spots)
+    tips = set(cast(HamiltonTip, op.tip) for op in ops)
     if len(tips) > 1:
       raise ValueError("Cannot mix tips with different tip types.")
     ttti = await self.get_or_assign_tip_type_index(tips.pop())
@@ -1484,9 +1483,9 @@ async def pick_up_tips(
     max_tip_length = max((op.tip.total_tip_length - op.tip.fitting_depth) for op in ops)
 
     # not sure why this is necessary, but it is according to log files and experiments
-    if self._get_hamilton_tip([op.resource for op in ops]).tip_size == TipSize.LOW_VOLUME:
+    if self._get_hamilton_tip([op.tip for op in ops]).tip_size == TipSize.LOW_VOLUME:
       max_tip_length += 2
-    elif self._get_hamilton_tip([op.resource for op in ops]).tip_size != TipSize.STANDARD_VOLUME:
+    elif self._get_hamilton_tip([op.tip for op in ops]).tip_size != TipSize.STANDARD_VOLUME:
       max_tip_length -= 2
 
     tip = ops[0].tip

pylabrobot/legacy/liquid_handling/backends/hamilton/STAR_tests.py

@@ -1178,6 +1178,13 @@ async def test_core_96_tip_pickup(self):
       ]
     )
 
+  async def test_tip_tracking_pick_up(self):
+    set_tip_tracking(enabled=True)
+    try:
+      await self.lh.pick_up_tips(self.tip_rack["A1", "B1"])
+    finally:
+      set_tip_tracking(enabled=False)
+
   async def test_tip_tracking_pick_up96(self):
     set_tip_tracking(enabled=True)
     await self.lh.pick_up_tips96(self.tip_rack)

pylabrobot/legacy/liquid_handling/backends/hamilton/base.py

@@ -21,7 +21,7 @@
   LiquidHandlerBackend,
 )
 from pylabrobot.legacy.liquid_handling.standard import PipettingOp
-from pylabrobot.resources import TipSpot
+from pylabrobot.resources import Tip
 from pylabrobot.resources.hamilton import (
   HamiltonTip,
   TipPickupMethod,
@@ -454,15 +454,14 @@ async def get_or_assign_tip_type_index(self, tip: HamiltonTip) -> int:
 
     return self._tth2tti[tip_type_hash]
 
-  def _get_hamilton_tip(self, tip_spots: List[TipSpot]) -> HamiltonTip:
-    """Get the single tip type for all tip spots. If it does not exist or is not a HamiltonTip,
-    raise an error."""
-    tips = set(tip_spot.get_tip() for tip_spot in tip_spots)
-    if len(tips) > 1:
+  def _get_hamilton_tip(self, tips: Sequence[Tip]) -> HamiltonTip:
+    """Get the single Hamilton tip type. If mixed or not a HamiltonTip, raise an error."""
+    unique = set(tips)
+    if len(unique) > 1:
       raise ValueError("Cannot mix tips with different tip types.")
-    if len(tips) == 0:
+    if len(unique) == 0:
       raise ValueError("No tips specified.")
-    tip = tips.pop()
+    tip = unique.pop()
     if not isinstance(tip, HamiltonTip):
       raise ValueError(f"Tip {tip} is not a HamiltonTip.")
     return tip

pylabrobot/legacy/liquid_handling/backends/hamilton/vantage_backend.py

@@ -484,17 +484,17 @@ async def pick_up_tips(
   ):
     x_positions, y_positions, tip_pattern = self._ops_to_fw_positions(ops, use_channels)
 
-    tips = [cast(HamiltonTip, op.resource.get_tip()) for op in ops]
+    tips = [cast(HamiltonTip, op.tip) for op in ops]
     ttti = [await self.get_or_assign_tip_type_index(tip) for tip in tips]
 
     max_z = max(op.resource.get_location_wrt(self.deck).z + op.offset.z for op in ops)
     max_total_tip_length = max(op.tip.total_tip_length for op in ops)
     max_tip_length = max((op.tip.total_tip_length - op.tip.fitting_depth) for op in ops)
 
     # not sure why this is necessary, but it is according to log files and experiments
-    if self._get_hamilton_tip([op.resource for op in ops]).tip_size == TipSize.LOW_VOLUME:
+    if self._get_hamilton_tip([op.tip for op in ops]).tip_size == TipSize.LOW_VOLUME:
       max_tip_length += 2
-    elif self._get_hamilton_tip([op.resource for op in ops]).tip_size != TipSize.STANDARD_VOLUME:
+    elif self._get_hamilton_tip([op.tip for op in ops]).tip_size != TipSize.STANDARD_VOLUME:
       max_tip_length -= 2
 
     try:

pylabrobot/legacy/liquid_handling/backends/hamilton/vantage_tests.py

@@ -360,6 +360,13 @@ async def test_tip_pickup_01(self):
       PICKUP_TIP_FORMAT,
     )
 
+  async def test_tip_tracking_pick_up(self):
+    set_tip_tracking(enabled=True)
+    try:
+      await self.lh.pick_up_tips(self.tip_rack["A1", "B1"])
+    finally:
+      set_tip_tracking(enabled=False)
+
   async def test_tip_drop_01(self):
     await self.test_tip_pickup_01()  # pick up tips first
     await self.lh.drop_tips(self.tip_rack["A1", "B1"])

pylabrobot/resources/tip_tracker.py

@@ -57,15 +57,15 @@ def has_tip(self) -> bool:
     return self._pending_tip is not None
 
   def get_tip(self) -> "Tip":
-    """Get the tip. Note that does includes pending operations.
+    """Get the tip. Note that this includes pending operations.
 
     Raises:
       NoTipError: If the tip spot does not have a tip.
     """
 
-    if self._tip is None:
+    if self._pending_tip is None:
       raise NoTipError(f"{self.thing} does not have a tip.")
-    return self._tip
+    return self._pending_tip
 
   def disable(self) -> None:
     """Disable the tip tracker."""

pylabrobot/resources/tip_tracker_tests.py

@@ -43,3 +43,17 @@ def test_remove_tip(self):
 
     with self.assertRaises(NoTipError):
       tracker.get_tip()
+
+  def test_get_tip_includes_pending_add(self):
+    tracker = TipTracker(thing="tester")
+    tracker.add_tip(self.tip, commit=False)
+    self.assertEqual(tracker.has_tip, True)
+    self.assertEqual(tracker.get_tip(), self.tip)
+
+  def test_get_tip_includes_pending_remove(self):
+    tracker = TipTracker(thing="tester")
+    tracker.add_tip(self.tip)
+    tracker.remove_tip(commit=False)
+    self.assertEqual(tracker.has_tip, False)
+    with self.assertRaises(NoTipError):
+      tracker.get_tip()