NullPointerException when loading remote reference.

[tkrop]

Following simple API example

openapi: 3.0.0
info:
  x-api-id: 10eab089-30d0-4dd1-9be7-2948c322b82b
  x-audience: company-internal
  version: "0.1.0"
  title: "My API"

paths:
  /test:
    get:
      responses:
        200:
          description: test
          content:
            application/json:
              schema:
                type: object
                properties:
                    id:
                      type: string
                      format: uuid
                    created_at:
                      type: string
                      format: date-time
      parameters:
        - $ref: 'https://infrastructure-api-repository.zalandoapis.com/apis/401d47fe-1628-4bea-8243-32f45ce9913d/versions/1.0.1/revisions/6#/parameters/Consents'

loads a valid external reference that should work but creates creates a 500 - Internal Server Error response:

{
    "title":"Internal Server Error",
    "status":500,
    "detail":"check invocation failed: id=Z001 title=Path parameters validation checkName=checkSchemaOrContentProperty reason=java.lang.NullPointerException: parameter.name must not be null"
}

The details of the stack trace are

java.lang.RuntimeException: check invocation failed: id=Z001 title=Path parameters validation checkName=checkSchemaOrContentProperty reason=java.lang.NullPointerException: parameter.name must not be null
        at org.zalando.zally.core.RulesValidator.invoke(RulesValidator.kt:63) ~[zally-core-2.1.1-SNAPSHOT.jar!/:na]
        at org.zalando.zally.core.RulesValidator.validate(RulesValidator.kt:40) ~[zally-core-2.1.1-SNAPSHOT.jar!/:na]
        at org.zalando.zally.core.CompositeRulesValidator.validate(CompositeRulesValidator.kt:9) ~[zally-core-2.1.1-SNAPSHOT.jar!/:na]
        at org.zalando.zally.apireview.ApiViolationsController.validate(ApiViolationsController.kt:47) ~[classes!/:na]
        at jdk.internal.reflect.GeneratedMethodAccessor262.invoke(Unknown Source) ~[na:na]
...
Caused by: java.lang.NullPointerException: parameter.name must not be null
        at org.zalando.zally.ruleset.zally.PathParameterRule.checkSchemaOrContentProperty(PathParameterRule.kt:47) ~[zally-ruleset-zally-2.1.1-SNAPSHOT.jar!/:na]
        ... 98 common frames omitted

The failure looks like an authorization problem, however, while on first sight the referenced location looks fine, it contains another local reference that may create problems:

in: body
name: body
description: "Consent object"
required: true
schema:
  $ref: "#/definitions/Consents"

The problem here is that in: body is not allowed in this parameter list. Consequently, the parser seems to filter resulting in an empty parameter array element, which results in a null-name as the NPE is telling. Note: referencing in: query parameter is working fine, e.g. Services.

[vadeg]

@tkrop given that definitions field mentioned here

schema:
  $ref: "#/definitions/Consents"

doesn't exist in OpenAPI 3.0, but exist in Swagger 2.0 does this means that the referenced API uses Swagger 2.x?