Linting does not catch default value types not conforming to specified field type

[matt-duffett]

Redocly CLI does not seem to recognise when a fields default value does not conform to the type specified for that field. This also applies to the vscode extension.

Apologies if there is some config I am missing or already a plugin that adds this behaviour!

Steps to reproduce the behavior:

1. Given this OpenAPI file:

openapi: 3.0.0
info:
  description: Example
  title: Example
  version: 1.0.0
  license: 
    name: Example License
    url: foo
servers:
  - url: /apis/v0
paths:
  /foo:
    get: 
      operationId: getFoo
      summary: bar
      responses: 
        '200':
          description: successful operation
          content:
            application/json:
              schema:
                type: string
                default: 123
        '400':
          description: error 400
      security: 
        - foo_security:
          - read:foo
components: 
  securitySchemes:
    foo_security:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: /openId/token
          scopes:
            read:foo: read foo

2. Run redocly lint openapi.yaml
3. See output

Expected Behaviour

I would expect there to be a warning or error for the default value of 123 not to match the type of string.

Redocly Version(s)

1.17.1

Node.js Version(s)

20

[jeremyfiel]

linting is provided by two sources. Ajv JSON Schema validation per the schema and configurable rules.

JSON Schema does not consider the default keyword as a validation keyword, thus it only provides informational data about the data type, it is not used for validation. In JSON Schema land, this is called an annotation

I don't think Redocly has a configurable rule for default values. If you happen to write a new configurable rule, please consider sharing it with the Redocly CookBook

[lornajane]

Thanks @matt-duffett and @jeremyfiel . We have type checking on examples, but I don't think we have it on defaults now. It's a good suggestion, I'll leave this issue open in case others have thoughts about this feature.