"nullable: True" ignored if used together with allOf or oneOf

Open

#277 opened on Jan 13, 2021 5 comments 7 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty: 4/5
Estimated time: 3-5 days
Newbie friendliness: 25/100

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

Research direction

Reproduce the reported OpenAPI schema with nullable combined with oneOf or allOf and validate an instance containing None. Trace the validator entry point that handles nullable and composition keywords. Done means None is accepted when nullable is true without breaking oneOf or allOf validation, with regression coverage for the reported schema.

Written by the indexing model from the issue text.

Description

I have the following issue. drf-spectacular generates the following spec for enums (for example, for a building_type field which can be either "house" or "apartment" or null):

    WhateverObject:
      type: object
      properties:
        building_type:
          nullable: true
          oneOf:
          - $ref: '#/components/schemas/BuildingTypeEnum'
          - $ref: '#/components/schemas/NullEnum'
 
    BuildingTypeEnum:
      enum:
      - house
      - apartment
      type: string

    NullEnum:
      enum:
      - null

but when trying to validate data containing None for the building_type field I get this error:

Failed validating 'oneOf' in schema['properties']['building_type']:
    {'nullable': True,
     'oneOf': [{'$ref': '#/components/schemas/BuildingTypeEnum',
                'nullable': False,
                'x-scope': ['', '#/components/schemas/HomeProfile']},
               {'$ref': '#/components/schemas/NullEnum',
                'nullable': False,
                'x-scope': ['', '#/components/schemas/HomeProfile']}]}

On instance['building_type']:
    None
None is not valid under any of the given schemas

I think that None should be allowed if nullable: True is specified.

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

Contributor guide

Open the contributing guide

First steps

Read the whole issue, then the project's contributing guide.
Comment on the issue to say you are picking it up — it saves two people doing the same work.
Fork the repository and make your change on a branch.
Open a pull request that references the issue number.

Similar issues

create_predictable_zip member order differs on Windows for directory input Open

bug

Difficulty 2/5 1-3 hours Newbie friendliness 90/100

learningequality/ricecooker#747 · Opened Sep 23, 2026
[Anon] Mechanicum: skitarii as mechanicum allies rule Open

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

BSData/horus-heresy-3rd-edition#3171 · Opened Sep 23, 2026
CHANGELOG.md entries are too long to maintain, and their length is what makes every PR conflict expensive Open

enhancement

Difficulty 2/5 1-3 hours Newbie friendliness 72/100

lanl/PyBNF#809 · Opened Sep 23, 2026
[Bug]: PrevNextNodePostprocessor loses retrieved scores when neighbor windows overlap Open

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

run-llama/llama_index#23199 · Opened Sep 23, 2026
Cannot export point cloud without radius attribute Open

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

KhronosGroup/glTF-Blender-IO#2769 · Opened Sep 23, 2026

More Python issues