Discriminator for oneOf schemas ignored

Open

#66 opened on Jul 26, 2018 2 comments 5 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 35/100

Issue type: Bug
Clarity: Mostly clear
Activity status: Stale
Tech stack: openapi, python
Domain: api

Research direction

Start by locating the oneOf and discriminator validation entry points in the Python library, then reproduce the issue with the provided schema and request. Trace how the discriminator mapping selects a schema and compare the current generic error with the requested property-specific validation error. Done means the mapped schema is validated and invalid requests receive useful errors.

Written by the indexing model from the issue text.

Description

area/schema kind/enhancement

If a discriminator is set for a list of oneOf schemas only the matching schema should be validated against and therefore useful errors can be provided:

schema

requestBody:
  content:
    application/json:
      schema:
        oneOf:
          - $ref: '#/components/schemas/cat_type'
          - $ref: '#/components/schemas/dog_type'
        discriminator:
          propertyName: type
          mapping:
            cat: '#/components/schemas/cat_type'
            dog: '#/components/schemas/dog_type'

request

{'type': 'dog' ...}

If the request is invalid the validator raises: "Exactly one valid schema should be valid, None found."

But if there's a discriminator we know which schema to validate against and could provide a useful error message. Such as what property is missing or invalid.

Dominant language: Python
Stars: 368
Forks: 140
PR merge metrics: No merged PRs in 30d

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