[Feature] add support for OpenAPI 3.1

[asdfasdfasdfasdfasasdf]

tmp.yaml.txt
Describe the bug
The YAML file we use fails to be parsed. I believe have tracked it down to:
type:
- string

The error is shown as:
File "/home/***/.local/lib/python3.10/site-packages/openapi_parser/builders/schema.py", line 135, in create
raise ParserError(f"Invalid schema type '{schema_type}'") from None
openapi_parser.errors.ParserError: Invalid schema type '['string']'

I'm quite confident that the YAML syntax is correct. We use it just fine and Swagger does not complain.

To Reproduce
Use attached YAML file and type:
python3
from openapi_parser import parse
all_parse = parse('tmp.yaml')

Expected behavior
No error parsing the file.

System details (please complete the following information):

• OS: Kubuntu 22.04
• OpenAPI / Swagger version 3.1.0
• Python version 3.10.12

Additional context

[manchenkoff]

Hey @asdfasdfasdfasdfasasdf, looks like you are using type field as array instead of plain value, it should be like others in your specs:

openapi: 3.1.0
info:
  version: unknown
  title: unknown
  description: unknown
servers:
  - url: https://localhost
    description: unknown
paths:
  /slots:
    get:
      operationId: getSlots
      tags:
        - backplane
      responses:
        "200":
          description: Successful operation
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/slots"
components:
  schemas:
    slots:
      type: array
      items:
        $ref: "#/components/schemas/slot"
    object_create:
      type: object
      properties:
        id:
          type: integer
    slot:
      type: object
      properties:
        id:
          type: integer
        occupied:
          type: string
        enabled:
          type: boolean
        module:
          $ref: "#/components/schemas/slot_module"
    slot_module:
      type: object
      properties:
        serial:
          type: string # fixed line

[asdfasdfasdfasdfasasdf]

Hi and thanks for your quick reply.

I'm no expert in YAML, trying to get a hang of it.
I believe that we use the "- string" to handle cases where it can be a string or null. In these cases it looks like

    slot_module:  
      type: object  
      properties:  
        serial:  
          type:  
            - string  
            - 'null'

But in the code attached to this ticket, we only have 1 member in the array.

[manchenkoff]

I believe that we use the "- string" to handle cases where it can be a string or null. In these cases, it looks like

I see, but unfortunately, this is the wrong way of doing that in OpenAPI specs, you can check the details and example of a proper way of handling multiple types here in docs. Specifically in the Mixed Types section.

[asdfasdfasdfasdfasasdf]

In Open API 3.1 it seems as if it is allowed: OAI/OpenAPI-Specification#2244 (comment)

[manchenkoff]

@asdfasdfasdfasdfasasdf
Yeah, I think you're right, my bad. However, the problem is the current package supports only 3.0.* specs, so to solve that you can either roll your specs back to 3.0 or wait for the support of 3.1, but I cannot give you an exact deadline since I do not have enough time/support to deliver new big features right now.
By the way, feel free to contribute if you have some free time, I would be glad to help with that!