allow list of states in flaw filter

[costaconrado]

This PR changes flaw API to allow filtering by a list of workflow_state.

Closes OSIDB-2208.

[jsvob]

LGTM, I'm for merging this and discussing the nitpick asynchronously.

[jsvob]

Nitpick: The enum in openapi.yml seems kind of useful for knowing which values are valid. We are losing that usefulness here. I see that Flaw's cve_id has the same drawback in openapi.yml, so this PR already has a precedent that it is OK. I'd just like to discuss (even after merging this) whether we want to somehow improve openapi.yml for fields that use CharInFilter, and whether anyone would even care. @RedHatProductSecurity/osidb-devs thoughts?

[JakubFrejlach]

For cve_id I think it is kinda different as it is not an enum and the field is pretty self explanatory, but losing an enum values might be problematic for anyone who would like to work with the API. I posted some possible solutions below, not tested them thoroughly or sure about them, just something to think about.

[JakubFrejlach]

Sorry for sticking my nose into this but I've noticed during the standup that this is about filters so I might give a quick opinion on this. 😄

[JakubFrejlach]

I think this is not entirely correct as we lost information about possible values of the enum, this could be easily solved if you use a different filter for the workflow_state:

from django_filters.rest_framework import ChoiceFilter, BaseInFilter

class ChoiceInFilter(BaseInFilter, ChoiceFilter):
    """
    Filter for choice csv
    """

    pass
    
workflow_state = ChoiceInFilter(field_name="workflow_state")

[JakubFrejlach]

Actually this might not work correctly, there also exist MultipleChoiceFilter, not sure how that works, just pointing out that enum values should be exposed in the schema

[osoukup]

I am also in favor of finding a way how to preserve the enumeration values listed in the OpeAPI

[osoukup]

See my comment above. I forgot to request the change.

[costaconrado]

Makes sense, submitted the change suggested by @JakubFrejlach, thanks you all

[JakubFrejlach]

@costaconrado Actually I am not sure, but it might be necessary to explicitly list the choices via choices argument, I tried that quickly on my local instance and without the choices I was getting "Invalid option selected...." for valid options. https://django-filter.readthedocs.io/en/stable/ref/filters.html#choicefilter

workflow_state_choices = [
        (s.value, s.value) for s in Flaw.WorkflowState
    ]

something like this probably

[costaconrado]

@JakubFrejlach I believe I can use something like:
workflow_state = ChoiceInFilter(field_name="workflow_state", choices=WorkflowModel.WorkflowState.choices)

let me test it

[osoukup]

Much better 😺 thank you for addressing the feedback!