[OpenAPI v3.1] Arrays now (incorrectly?) parse to JsonSchema rather than ArraySchema

[dominic-jones]

In attempted to use swagger-codegen to read a 3.1.0 schema vs a 3.0.x schema, a notable change has occurred in how arrays are handled.

For example when provided the following path:

  /pets:
    post:
      requestBody:
        content:
          application/json:
            schema:
              type: array
              items:
                $ref: '#/components/schemas/Pet'
        required: true
      responses:
        '204':
          description: 'No Content'

This parses to an ArraySchema in 3.0.x, but now parses to JsonSchema in 3.1.0. This could be intentional, as it sounds like some changes occurred in the structure of these objects for 3.1.0, but I'm not yet sure. I'm already multiple layers deep from my organisation, and our change will be to use 3.0.x for the time being, but leaving a report here.

swagger-codegen relies on this ArraySchema usage. The resultant codegen defaults to Object instead.

Example displaying this issue: dominic-jones@bec6fab

[rob-spoor]

I think I have the same issue, but on a much larger scale. With a version 3.0.x in the OpenAPI spec file, components get parsed to different types like ObjectSchema, ArraySchema, etc. When we only change the version to 3.1.0 in the spec file, they all become JsonSchema. That means we need to start parsing these JsonSchema instances again to determine how to handle it: we need to check several properties like type, $ref, allOf, oneOf, anyOf, etc., instead of being able to use switch expressions to check on the type. That makes it a lot more difficult to work with version 3.1.0 documents.

I've traced it back to ModelDeserializer which simply says "if the version is 3.1.x then deserialize as JsonSchema". Otherwise it creates the different Schema sub types that both you and I expected. It would be great to be able to set an option to parse the old 3.0.x way.