[Bug]: encoding not supported for individual requestBody properties

[andersk]

Actual Behavior

OpenAPI allows specifying an application/x-www-form-urlencoded request body that contains individual application/json encoded properties, by using the contentType field of the encoding object. The Swagger specification shows an example of this (under “Complex Serialization in Form Data”, and reproduced below). However, openapi-core ignores the contentType field and fails to validate a valid request against such a spec.

Traceback (most recent call last):
  File "/home/anders/python/openapi-core/openapi_core/validation/decorators.py", line 31, in wrapper
    return f(*args, **kwds)
  File "/home/anders/python/openapi-core/openapi_core/validation/request/validators.py", line 253, in _get_body
    return self._get_content_value(raw_body, mimetype, content)
  File "/home/anders/python/openapi-core/openapi_core/validation/validators.py", line 126, in _get_content_value
    self._validate_schema(schema, casted)
  File "/home/anders/python/openapi-core/openapi_core/validation/validators.py", line 102, in _validate_schema
    validator.validate(value)
  File "/home/anders/python/openapi-core/openapi_core/validation/schemas/validators.py", line 36, in validate
    raise InvalidSchemaValue(value, schema_type, schema_errors=errors)
openapi_core.validation.schemas.exceptions.InvalidSchemaValue: Value {'payload': '{"text":"Swagger is awesome"}'} not valid for schema of type object: (<ValidationError: '\'{"text":"Swagger is awesome"}\' is not of type \'object\''>,)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/anders/python/openapi-core/post_encoding_test.py", line 65, in <module>
    validate_request(request, spec=spec)
  File "/home/anders/python/openapi-core/openapi_core/shortcuts.py", line 305, in validate_request
    validate_apicall_request(
  File "/home/anders/python/openapi-core/openapi_core/shortcuts.py", line 379, in validate_apicall_request
    return v.validate(request)
  File "/home/anders/python/openapi-core/openapi_core/validation/request/validators.py", line 269, in validate
    raise err
  File "/home/anders/python/openapi-core/openapi_core/validation/request/validators.py", line 110, in _iter_errors
    self._get_body(request.body, request.mimetype, operation)
  File "/home/anders/python/openapi-core/openapi_core/validation/decorators.py", line 33, in wrapper
    self._raise_error(exc, self.err_validate_cls, f, *args, **kwds)
  File "/home/anders/python/openapi-core/openapi_core/validation/decorators.py", line 58, in _raise_error
    raise init(**kw) from exc
openapi_core.validation.request.exceptions.InvalidRequestBody: Request body validation error

Expected Behavior

This request should successfully validate.

Steps to Reproduce

import yaml
from urllib.parse import urlencode

from openapi_core import Spec
from openapi_core import validate_request
from openapi_core.testing import MockRequest

SPEC = r"""
openapi: 3.0.0
info:
  version: 1.0.0
  title: Slack Incoming Webhook
externalDocs:
  url: https://api.slack.com/incoming-webhooks

servers:
  - url: https://hooks.slack.com

paths:
  /services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX:
    post:
      summary: Post a message to Slack
      requestBody:
        content:

          application/json:
            schema:
              $ref: '#/components/schemas/Message'

          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                payload:     # <--- form field that contains the JSON message
                  $ref: '#/components/schemas/Message'
            encoding:
              payload:
                contentType: application/json

      responses:
        '200':
          description: OK

components:
  schemas:
    Message:
      title: A Slack message
      type: object
      properties:
        text:
          type: string
          description: Message text
      required:
        - text
"""

spec = Spec.from_dict(yaml.safe_load(SPEC))
request = MockRequest(
    "https://hooks.slack.com/",
    "post",
    "/services/T00000000/B00000000/XXXXXXXXXXXXXXXXXXXXXXXX",
    data=urlencode({"payload": '{"text":"Swagger is awesome"}'}),
    mimetype="application/x-www-form-urlencoded",
)
validate_request(request, spec=spec)

OpenAPI Core Version

0.18.0

OpenAPI Core Integration

none

Affected Area(s)

No response

References

No response

Anything else we need to know?

No response

Would you like to implement a fix?

None

[andersk]

This doesn’t work for array parameters:

• [Bug]: UnboundLocalError: local variable 'value' referenced before assignment #696