Migrate to OpenAPI 3.1

[ai-oleynikov]

This PR updates OpenAPI version from 3.0 to 3.1 in accordance with this guide: https://www.openapis.org/blog/2021/02/16/migrating-from-openapi-3-0-to-3-1-0

The only changes I made are:

• deletion of "nullable": false as this keyword is now deprecated, and nulls are rejected by default anyway
• replacement of "type": "<some-type>", "nullable": true with "type": ["<some-type>", "null"]
• replacement of "minimum": 0, "exclusiveMinimum": true with "exclusiveMinimum": 0
• replacement of "example" with "examples" keyword inside Schema Objects

[ai-oleynikov]

This one change is unrelated to the migration to OpenAPI 3.1. I just couldn't ignore it. "Crowdfunding app" sounds more natural. Feel free to revert this change if you disagree though.

[dennisreimann]

LGTM

[Kukks]

The swagger schema test fails. Please check CheckSwaggerIsConformToSchema

[dennisreimann]

It looks like the Newtonsoft JSchema package has problems parsing th OpenAPI 3.1 spec. Updated the lib and tried various approaches, but it fails with Error when resolving schema reference '#/$defs/info'. Path 'properties.info', line 11, position 13, which one can also replicate with their JSON Schema Validator (select the openapi.json from the dropdown).

[dennisreimann]

Rebased and tried to make the schema validation work by removing the $id attribute, which prevented that the references worked in general. But now there is still an error with nested $defs: Could not resolve schema reference '#/$defs/parameter/dependentSchemas/schema/$defs/styles-for-path'. Path '$defs.parameter.dependentSchemas.schema.allOf[1]'

[dennisreimann]

@ai-oleynikov Any idea how we can resolve this?

[pavlenex]

ping @ai-oleynikov still interested in helping with this one, if so can you check ^

[ai-oleynikov]

Sorry for my disappearance! I'll work on fixing this today and report back if I have any issues I can't resolve.

[ai-oleynikov]

The problem seems to be that JSchema doesn't support the current version of the JSON Schema spec.

https://www.jsonschemavalidator.net/ says the following

An online, interactive JSON Schema validator. Supports JSON Schema Draft 3, Draft 4, Draft 6, Draft 7 and Draft 2019-09.

Therefore. it can't parse JSON Schema 2020-12. The error messages @dennisreimann shared above indicate that JSchema is unable to resolve references containing $defs, likely due to the changes in the behavior of $defs introduced in JSON Schema 2020-12.

Unfortunately, the OpenAPI Initiative doesn't provide a JSON Schema for OpenAPI 3.1 using spec versions other than 2020-12. All their schema files are written using this version.

I'm not sure what can be done here, except replacing JSchema with another JSON Schema validator that supports the current version of the spec 🤔

[ai-oleynikov]

This package seems to support JSON Schema draft 2020-12: https://www.nuget.org/packages/JsonSchema.Net