fix volume tracking on dispense96

Author: rickwierenga

pylabrobot/liquid_handling/liquid_handler.py

@@ -1742,18 +1742,13 @@ async def dispense96(
         raise ValueError("Container too small to accommodate 96 head")
 
       for channel in self.head96.values():
-        # superfluous to have append in two places but the type checker is very angry and does not
-        # understand that Optional[Liquid] (remove_liquid) is the same as None from the first case
-        reversed_liquids: List[Tuple[Optional[Liquid], float]]
-        if container.tracker.is_disabled or not does_volume_tracking():
-          reversed_liquids = [(None, volume)]
-          all_liquids.append(reversed_liquids)
-        else:
-          reversed_liquids = container.tracker.remove_liquid(volume=volume)  # type: ignore
-          all_liquids.append(reversed_liquids)
+        liquids = channel.get_tip().tracker.remove_liquid(volume=volume)
+        reversed_liquids = list(reversed(liquids))
+        all_liquids.append(reversed_liquids)
 
-        for liquid, vol in reversed(reversed_liquids):
-          channel.get_tip().tracker.add_liquid(liquid=liquid, volume=vol)
+        if not container.tracker.is_disabled and does_volume_tracking():
+          for liquid, vol in reversed(reversed_liquids):
+            container.tracker.add_liquid(liquid=liquid, volume=vol)
 
       dispense = MultiHeadDispenseContainer(
         container=container,
@@ -1765,8 +1760,6 @@ async def dispense96(
         blow_out_air_volume=blow_out_air_volume,
         liquids=cast(List[List[Tuple[Optional[Liquid], float]]], all_liquids),  # stupid
       )
-
-      containers = [resource]
     else:
       # ensure that wells are all in the same plate
       plate = containers[0].parent
@@ -1803,13 +1796,13 @@ async def dispense96(
       await self.backend.dispense96(dispense=dispense, **backend_kwargs)
     except Exception as error:
       for channel, container in zip(self.head96.values(), containers):
-        if does_volume_tracking() and not well.tracker.is_disabled:
+        if does_volume_tracking() and not container.tracker.is_disabled:
           container.tracker.rollback()
         channel.get_tip().tracker.rollback()
       raise error
     else:
       for channel, container in zip(self.head96.values(), containers):
-        if does_volume_tracking() and not well.tracker.is_disabled:
+        if does_volume_tracking() and not container.tracker.is_disabled:
           container.tracker.commit()
         channel.get_tip().tracker.commit()
 

pylabrobot/liquid_handling/liquid_handler_tests.py

@@ -25,6 +25,7 @@
   ResourceNotFoundError,
   ResourceStack,
   TipRack,
+  nest_1_troughplate_195000uL_Vb,
   no_tip_tracking,
   set_tip_tracking,
 )
@@ -1038,9 +1039,11 @@ async def asyncSetUp(self):
     self.deck = STARLetDeck()
     self.lh = LiquidHandler(backend=self.backend, deck=self.deck)
     self.tip_rack = STF(name="tip_rack")
-    self.plate = Cor_96_wellplate_360ul_Fb(name="plate")
     self.deck.assign_child_resource(self.tip_rack, location=Coordinate(0, 0, 0))
+    self.plate = Cor_96_wellplate_360ul_Fb(name="plate")
     self.deck.assign_child_resource(self.plate, location=Coordinate(100, 100, 0))
+    self.single_well_plate = nest_1_troughplate_195000uL_Vb(name="single_well_plate")
+    self.deck.assign_child_resource(self.single_well_plate, location=Coordinate(300, 100, 0))
     await self.lh.setup()
     set_volume_tracking(enabled=True)
 
@@ -1091,7 +1094,7 @@ async def error_func(*args, **kwargs):
     # test volume doens't change on failed dispense
     assert self.lh.head[0].get_tip().tracker.get_used_volume() == 200
 
-  async def test_96_head_volume_tracking(self):
+  async def test_96_head_volume_tracking_multi_container(self):
     for item in self.plate.get_all_items():
       item.tracker.set_liquids([(Liquid.WATER, 10)])
     await self.lh.pick_up_tips96(self.tip_rack)
@@ -1103,6 +1106,22 @@ async def test_96_head_volume_tracking(self):
     for i in range(96):
       self.assertEqual(self.lh.head96[i].get_tip().tracker.get_used_volume(), 0)
       self.plate.get_item(i).tracker.get_used_volume() == 10
+    await self.lh.return_tips96()
+
+  async def test_96_head_volume_tracking_single_container(self):
+    well = self.single_well_plate.get_item(0)
+    well.tracker.set_liquids([(Liquid.WATER, 10 * 96)])
+    await self.lh.pick_up_tips96(self.tip_rack)
+
+    await self.lh.aspirate96(self.single_well_plate, volume=10)
+    assert all(self.lh.head96[i].get_tip().tracker.get_used_volume() == 10 for i in range(96))
+    assert well.tracker.get_used_volume() == 0
+
+    await self.lh.dispense96(self.single_well_plate, volume=10)
+    assert all(self.lh.head96[i].get_tip().tracker.get_used_volume() == 0 for i in range(96))
+    assert well.tracker.get_used_volume() == 10 * 96
+
+    await self.lh.return_tips96()
 
 
 class TestLiquidHandlerCrossContaminationTracking(unittest.IsolatedAsyncioTestCase):