Here are some highlights of my tests :

>>> assets = kili.assets(project_id=project_id, step_status_in=['TO_DO'])

UserWarning: Field status requested : request fields step and stepStatus instead for this project

-> we should not pass status by default in fields if the project is in workflow V2, to avoid a warning if user does not specify fields explicitly

>>> assets = kili.assets(project_id=project_id, step_in=['Labeling'])
>>> print(len(assets))
6
>>> assets = kili.assets(project_id=project_id, step_in=['Reviewing 1'])
>>> print(len(assets))
1
>>> assets = kili.assets(project_id=project_id, step_in=['????'])
>>> print(len(assets))
7

-> I think we should add a validator on step_in to only allow valid values, and raise if the step name is invalid (like for step_status_in)
-> Suggestion : rename step_in to step_name_in ? At first, I thought it was step ids - might be confusing for user
-> Should not the step name be Label and Review 1 ? (as you're currently refactoring it, I don't know if it's need to be in this MR)

>>> assets = kili.assets(project_id=project_id, step_status_in=['DOING'])
>>> print(len(assets))
1

>>> assets = kili.assets(project_id=project_id, status_in=['ONGOING'])
>>> print(len(assets))
UserWarning: Field status requested : request fields step and stepStatus instead for this project
0

-> I think it would be better to raise if user request fields forbidden in workflow V2 (and vice-versa) to avoid incorrect results

>>> assets = kili.assets(project_id=project_id, step_status_in=['SKIPPED'], skipped=True)
>>> print(len(assets))
UserWarning: Filter skipped given : use filter step_status_in with the SKIPPED status instead for this project
1
>>> assets = kili.assets(project_id=project_id, skipped=True)
>>> print(len(assets))
1

-> I think this user warning should be present even if the user did not specify step_status_in

As discussed with @paulruelle :

• "not pass status by default in fields" : not resolved here. We will not modify this because the default project are not workflowV2 yet. When it will be the case, we can modify accordingly.
• "validator on step_in" : added a validation on step names
• "rename step_in to step_name_in" : renamed accordingly
• "Should not the step name be Label and Review 1" : this is not addressed here : ticket Lab-3565 does the trick.
• "I think it would be better to raise if user request fields forbidden in workflow V2 (and vice-versa) to avoid incorrect results" : there are a few cases. In some cases, we trigger a warning, in other we trigger errors (as identified on the ticket)
• "I think this user warning should be present even if the user did not specify step_status_in" : added a verification in this case
• "I would move step_in and step_status_in just below status_in, to enhance documentation readability" : moved sections closer to each other