List query parameter is not marked required?

tapir
1

Hello, i was wondering if it’s possible in tapir to mark query parameters that accept lists to be required?

I Have a query on my endpoint that looks like:
query[List[String]]("metric")

which works, but the query parameter is not marked as required in the openapi spec…

- name: metric
        in: query
        required: false
        schema:
          type: array
          items:
            type: string

Is this intentional? Is there a way to mark this as required without manipulating the openapi object directly?

Thanks,
ben

2

Yes, it’s intentional, as if no parameter is provided, the list will be empty.

One possibility is to use a dedicated data type for non-empty lists, such as NonEmptyList from cats-effect. See the cats integration.

Another is to modify the schema attached to the query parameter:

query[List[String]]("metric").schema(_.copy(isOptional = false))

However, this won’t validate that the list is indeed non-empty. For this, you’d need to change the codec as well, for example following the implementation for the above mentioned NonEmptyList.

3

Cats it is then!

Thanks