fix(protocol-designer): fix no tiprack-related whitescreen

[ncdiehl11]

Overview

This PR fixes a PD whitescreen bug where a user tries to create a transfer step wihout a tiprack available on the deck. As a temporary fix, I null check the first tiprack option in TiprackField and default to a placeholder string. This prevents a whitescreen, and creates a not-enough-tips timeline error if the step is saved, instructing the user to add tipracks to the deck to fix.

Closes RESC-380

Test Plan and Hands on Testing

• create a protocol with a wellplate
• delete all tiprack instances
• create a transfer step and verify that no whitescreen occurs, and that the tiprack field defaults to "No tiprack available"
• fill out the form and save
• verify that a not-enough-tips timeline error is shown

Changelog

• null check tiprack list in TiprackField
• add translation

Review requests

see test plan

Risk assessment

low

[jerader]

lgtm, do we follow the same pattern for when there are no lawares available for that dropdown? i feel like we say "choose option" or something

[ncdiehl11]

lgtm, do we follow the same pattern for when there are no lawares available for that dropdown? i feel like we say "choose option" or something

Yes we show a dropdown option that is not Interactable. I just brought this up with Mel who is giving it a think. For now, the resolution is to leave it alone.