feat(step-generation): py command generation for mix()

[jerader]

closes AUTH-1097

Overview

this PR introduces the py command generation for mix()! It is emitted only if there are acceptable args. Meaning no aspirate delay, no dispense delay.

TODO: figure out the flow rates! user can specify both aspirate and dispense flow rates but mix can only use one. how do we know which one to use?

Test Plan and Hands on Testing

Review the code and smoke test

here is an example i made that passes analysis for the different variations of commands

from contextlib import nullcontext as pd_step
from opentrons import protocol_api, types

metadata = {
    "protocolName": "test mixing",
    "created": "2025-03-20T17:54:17.554Z",
    "lastModified": "2025-03-20T17:55:04.093Z",
    "protocolDesigner": "8.4.3",
    "source": "Protocol Designer",
}

requirements = {
    "robotType": "Flex",
    "apiLevel": "2.23",
}

def run(protocol: protocol_api.ProtocolContext):
    # Load Labware:
    tip_rack_1 = protocol.load_labware(
        "opentrons_flex_96_tiprack_50ul",
        "C2",
        namespace="opentrons",
        version=1,
    )
    reservoir_1 = protocol.load_labware(
        "axygen_1_reservoir_90ml",
        "D1",
        namespace="opentrons",
        version=2,
    )

    # Load Pipettes:
    pipette_left = protocol.load_instrument("flex_1channel_50", "left", tip_racks=[tip_rack_1])

    # Load Trash Bins:
    trash_bin_1 = protocol.load_trash_bin("A3")

    # PROTOCOL STEPS

    # Step 1: NO MIX SINCE DELAY IS SET
    pipette_left.pick_up_tip(location=tip_rack_1)
    pipette_left.configure_for_volume(10)
    pipette_left.aspirate(
        volume=10,
        location=reservoir_1["A1"].bottom(z=1),
        rate=35 / pipette_left.flow_rate.aspirate,
    )
    protocol.delay(seconds=10)
    pipette_left.dispense(
        volume=10,
        location=reservoir_1["A1"].bottom(z=1),
        rate=57 / pipette_left.flow_rate.dispense,
    )
    protocol.delay(seconds=10)
    pipette_left.aspirate(
        volume=10,
        location=reservoir_1["A1"].bottom(z=1),
        rate=35 / pipette_left.flow_rate.aspirate,
    )
    protocol.delay(seconds=10)
    pipette_left.dispense(
        volume=10,
        location=reservoir_1["A1"].bottom(z=1),
        rate=57 / pipette_left.flow_rate.dispense,
    )
    protocol.delay(seconds=10)
    pipette_left.drop_tip()

    # Step 2: MIX SINCE DELAY IS NOT SET
    pipette_left.pick_up_tip(location=tip_rack_1)
    pipette_left.configure_for_volume(10)
    pipette_left.flow_rate.aspirate = 35
    pipette_left.flow_rate.dispense = 57
    pipette_left.mix(
        repetitions=2,
        volume=10,
        location=reservoir_1["A1"].bottom(z=1),
    )
    pipette_left.flow_rate.blow_out = 57
    pipette_left.blow_out(trash_bin_1)
    pipette_left.touch_tip(
        reservoir_1["A1"],
        v_offset=-1,
    )
    pipette_left.drop_tip()

Changelog

• py command for mix() in the mixUtil
• add test cases for the different py command variations
• extend util to include invariant context and plug into all usages of the util

Risk assessment

low, behind a ff

[codecov]

Codecov Report

Attention: Patch coverage is 98.80952% with 1 line in your changes missing coverage. Please review.

Project coverage is 63.24%. Comparing base (c7bcbad) to head (4439db3).
Report is 9 commits behind head on edge.

Files with missing lines	Patch %	Lines
...ration/src/commandCreators/compound/consolidate.ts	66.66%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             edge   #17833       +/-   ##
===========================================
+ Coverage   23.41%   63.24%   +39.83%     
===========================================
  Files        2891     2891               
  Lines      222561   223631     +1070     
  Branches    19013    19545      +532     
===========================================
+ Hits        52115   141438    +89323     
+ Misses     170435    82008    -88427     
- Partials       11      185      +174     

Flag	Coverage Δ
protocol-designer	19.06% <90.47%> (+0.20%)	⬆️
step-generation	4.37% <98.80%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
shared-data/command/types/index.ts	100.00% <100.00%> (ø)
...eration/src/commandCreators/compound/distribute.ts	93.30% <100.00%> (-1.30%)	⬇️
...tep-generation/src/commandCreators/compound/mix.ts	88.56% <100.00%> (+1.69%)	⬆️
...eneration/src/commandCreators/compound/transfer.ts	95.14% <100.00%> (-1.03%)	⬇️
...ration/src/commandCreators/compound/consolidate.ts	94.63% <66.66%> (-1.02%)	⬇️

... and 1696 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[jerader]

need to figure out how to show both flow rates or if we have to remove one?

[jerader]

okay discussed with jeremy in standup and actually we can just define it above the mix()

like this

mockPythonName.mix(
    repetitions=2,
    volume=5,
    location=mockPythonName["C1"].bottom(z=3.2),
)