[PJL-10221] handle some edge cases in OpenAPI v3.1 swagger generation

[dekim24]

Change 1

Right now, ContainsOnly validators are being handled identically to OneOf validators. This is because, in Marshmallow, ContainsOnly is a subclass of OneOf. However, this isn't actually correct because the logic is different -

• ContainsOnly: Validator which succeeds if value is a sequence and each element in the sequence is also in the sequence passed as choices.
• OneOf: Validator which succeeds if value is a member of choices.

I added a separate validator to handle ContainsOnly and validated that it produces the expected output against one of our repos (PADD). You can see in the below screenshot that we were incorrectly specifying the enum: parameter at the level of the value itself (which causes an error if you run this against an OpenAPI validator, because you're comparing an array to a string) when the enum: should actually be at under the items:.

Change 2

In OpenAPI 3 https://swagger.io/docs/specification/v3_0/data-models/dictionaries/ we are able to specify the allowed types of dictionary values (keys must always be strings so there is no need to specify their type) in the swagger file. The corresponding marshmallow param would be values. I added logic to factor in any schema passed into the values param and generate it in the swagger file. I also tested this on PADD and got expected results.

[dekim24]

this is messy but I couldn't figure out a better way to figure out the type of the parent value when the obj we are passed is the marshmallow.validator i.e. 1 level inside the value.

[auramix]

Thanks for fixing this bug and contributing to flask-rebar, Eugene. Test cases look good-- happy to approve this.

I will add a link to this PR in the open issue from 2020 and mark it as closed: #183

EDIT: Actually, this is looking like a 2-for-1 : #310 🙌 🎉