Lint error: Expected type Schema (object) but got boolean appears when linting API definition

[ZyzychO]

Describe the bug

Upon linting a valid API Definition, the error message "Expected type Schema (object) but got boolean" appears

To Reproduce
Steps to reproduce the behavior:

1. Given this redocly.yaml file:
   redocly.yaml.zip

2. And this OpenAPI file
   openapi.yaml.zip

3. Run this command: redocly lint openapi.yaml

4. See error: Expected type Schema (object) but got boolean

Expected behavior

In accordance with JSON Schema documentation:
https://json-schema.org/understanding-json-schema/reference/object#extending, in order to extend closed schemas you can write your schema as in the example below:

components:
  schemas:
    MyObject:
      type: object
      additionalProperties: false
      allOf:
        - $ref: '#/components/schemas/MyObjectBase'
      properties:
        property1: true
        property2: true 
      required:
        - property2
    MyObjectBase:
      type: object
      properties:
        property1:
          type: string
        property2:
          type: string
      required:
        - property1
       

However, it seems Redocly CLI does not cover this use case since the error message occurs:

Front conversations

[jeremyfiel]

seems like your indentation is incorrect. the second allOf schema should be under an array - definition

components:
  schemas:
    MyObject:
      type: object
      additionalProperties: false
      allOf:
        - $ref: '#/components/schemas/MyObjectBase'
        - properties:
            property1: true
            property2: true 
          required:
            - property2
    MyObjectBase:
      type: object
      properties:
        property1:
          type: string
        property2:
          type: string
      required:
        - property1
       

[jeremyfiel]

Does this solve your issue? Can this be closed?

[tatomyr]

@jeremyfiel I don't think it does. The issue is that the linter doesn't recognise a boolean value of properties. And I don't know if it's better to allow the booleans or use unevaluatedProperties (like in this example) instead of additionalProperties + boolean properties.

[lornajane]

Thanks everyone for the clear explanations. It's a valid bug IMO, although kind of an edge case for a specific way to extend a closed schema, I'm actually not sure I've seen this usage before in an OpenAPI context. For organisations who do control their own schemas, I think enabling additionalProperties on the base schema, or refactoring the structure would be a good workaround while we consider how to prioritise adding support for this case.

[jeremyfiel]

It depends which version of OAS they are using to determine if this is a bug or not. In JSON Schema draft 7+, it is valid to have a Boolean schema or an object schema but that requires the use of OAS 3.1.x. if using OAS 3.0.x, Boolean schemas were not allowed and must be an empty schema property:{}, in which case this would not be a valid use case and the error is correctly reporting. I figured this usage was intended to be an allOf array of schemas and their indentation was incorrect. I suppose they can also write their schema in the way they've written it, although they need to adjust it with the empty schema.