OpenAPI 3.0.0 specification is treated as invalid

[cpkio]

Describe the bug

Schema: https://raw.githubusercontent.com/OAI/OpenAPI-Specification/main/schemas/v3.0/schema.yaml is treated as invalid.

OpenAPI issue #2969.

Expected Behavior

Should be considered valid.

Current Behavior

Result: Schema 'schema.yaml' is not valid: /definitions/Schema/properties/multipleOf/exclusiveMinimum : must be number

Steps to Reproduce

1. Set # yaml-language-server: $schema=https://raw.githubusercontent.com/OAI/OpenAPI-Specification/main/schemas/v3.0/schema.yaml in Neovim modeline in OpenAPI specification file.
2. Set openapi: 3.0.0 in this OpenAPI specification file.

Schema 3.1.0 works fine.

Environment

• Windows

[okybr]

you can use this patch in order to use draft-04 which is needed for openapi-3.0-schema: okybr@455d452

also check out this readme: https://github.com/okybr/yaml-language-server#readme

[Davidonium]

After encountering this same issue and digging through why this happens, I believe that the issue is that ajv, the library used for json schema validation, does not support the draft-04 version because there's no security support for it.
See:

• The line having ajv v8 as a dep https://github.com/redhat-developer/yaml-language-server/blob/main/package.json#L33
• The docs that say there's no support in ajv and prompt the user to use v6 https://ajv.js.org/guide/schema-language.html#draft-04

[Davidonium]

I gave a stab supporting this in the PR that was linked. Let me know what you all think!