[Feature]: Support for OpenAPI Spec 3.2

[caochenlei]

Feature Description

Add support for parsing and validating OpenAPI Specification 3.2.0. This update addresses the gap in current swagger-parser capabilities where only older OpenAPI versions are supported, preventing users from leveraging the latest specification features and improvements.

Use Case

1. Modern API Development: Teams adopting OpenAPI 3.2.0 for new API specifications cannot use swagger-parser for validation, documentation generation, or code generation workflows
2. Migration Projects: Organizations upgrading from older OpenAPI versions (3.0.x, 3.1.x) to 3.2.0 need tooling support to validate their migrated specifications
3. CI/CD Pipelines: Automated API validation in deployment pipelines fails when encountering OpenAPI 3.2.0 specs, breaking development workflows
4. Toolchain Integration: Downstream tools that rely on swagger-parser (documentation generators, mock servers, client SDK generators) cannot process 3.2.0 specs

Suggested Solution (optional)

1. Schema Updates: Update the internal schema definitions to support OpenAPI 3.2.0 structure and validation rules
2. Version Detection: Enhance version parsing to recognize 3.2.0 in the openapi field
3. Backward Compatibility: Maintain support for existing OpenAPI versions while adding 3.2.0 capabilities
4. New Feature Support: Implement support for 3.2.0 specific features such as:
   • Updated JSON Schema dialect (2020-12)
   • New webhook object support
   • Enhanced security scheme features

Alternatives Considered

Additional Context

• OpenAPI 3.2.0 Release Notes: https://github.com/OAI/OpenAPI-Specification/releases/tag/3.2.0
• OpenAPI 3.2.0 Specification: https://spec.openapis.org/oas/v3.2.0
• Migration Guide: The 3.2.0 release is designed to be compatible with 3.1.0 with minimal breaking changes
• Industry Adoption: Growing number of API tools and platforms are adding 3.2.0 support

Checklist

• I have searched the existing issues to ensure this is not a duplicate.
• This feature would be useful to more than just my use case.
• I have provided enough detail for the maintainers to understand the scope of the request.

[baywet]

To add some context here, I implemented 3.2.0 support twice recently:

• Once in TypeScript: feat(openapi-types): OpenAPI 3.2 scalar/scalar#7039
• Once in Dotnet: feat!: adds support for OpenAPI 3.2.0 microsoft/OpenAPI.NET#2578

While the design choices might be different here, this should give a good overview of the required changes. The only things that's missing in those two PRs is the implementation of dynamic reference resolution.

I hope this helps :)

[beavuck]

Is this issue alive? I'm surprised it hasn't been acknowledged yet

EDIT: they are currently "working on OAS 3.2 support in editor", according to their recent community post #2284, and their ability to maintain swagger-parser has been "limited"