Unable to follow/detect model reference in another file ($ref)

Hi!

I first created this bug in swagger-codegen project ( https://github.com/swagger-api/swagger-codegen/issues/6813 ) but then I created a small project with swagger-parser and could reproduce the issue. It is definitely a bug is swagger-parser.

The problem is that swagger-parser doesn’t seems to follow $ref in other files, thus preventing the use of multi files specs. Is is supposed to be supported? Is there a problem in my spec? Is there any workarounds?

You can reproduce easily by loading this swagger.yaml file with swagger-parser. You will notice that there is no model in the POJO representation. Both files must be in the same folder.

This is swagger.yaml

swagger: '2.0'
info:
  version: '1.0.0'
  title: Swagger Petstore (Simple)
  description: A sample API that uses a petstore as an example to demonstrate features in the swagger-2.0 specification
  termsOfService: http://helloreverb.com/terms/
  contact:
    name: Swagger API team
    email: [e-mail]
    url: http://swagger.io
  license:
    name: MIT
    url: http://opensource.org/licenses/MIT
host: petstore.swagger.io
basePath: /api
schemes:
  - http
consumes:
  - application/json
produces:
  - application/json
paths:
  /pets:
    get:
      description: Returns all pets from the system that the user has access to
      operationId: findPets
      produces:
        - application/json
        - application/xml
        - text/xml
        - text/html
      parameters:
        - name: tags
          in: query
          description: tags to filter by
          required: false
          type: array
          items:
            type: string
          collectionFormat: csv
        - name: limit
          in: query
          description: maximum number of results to return
          required: false
          type: integer
          format: int32
      responses:
        '200':
          description: pet response
          schema:
            type: array
            items:
              $ref: 'definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: 'definitions.yaml#/definitions/errorModel'
    post:
      description: Creates a new pet in the store.  Duplicates are allowed
      operationId: addPet
      produces:
        - application/json
      parameters:
        - name: pet
          in: body
          description: Pet to add to the store
          required: true
          schema:
            $ref: 'definitions.yaml#/definitions/newPet'
      responses:
        '200':
          description: pet response
          schema:
            $ref: 'definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: 'definitions.yaml#/definitions/errorModel'
  /pets/{id}:
    get:
      description: Returns a user based on a single ID, if the user does not have access to the pet
      operationId: findPetById
      produces:
        - application/json
        - application/xml
        - text/xml
        - text/html
      parameters:
        - name: id
          in: path
          description: ID of pet to fetch
          required: true
          type: integer
          format: int64
      responses:
        '200':
          description: pet response
          schema:
            $ref: 'definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: 'definitions.yaml#/definitions/errorModel'
    delete:
      description: deletes a single pet based on the ID supplied
      operationId: deletePet
      parameters:
        - name: id
          in: path
          description: ID of pet to delete
          required: true
          type: integer
          format: int64
      responses:
        '204':
          description: pet deleted
        default:
          description: unexpected error
          schema:
            $ref: 'definitions.yaml#/definitions/errorModel'

This is definitions.yaml

definitions:
  pet:
    type: object
    required:
      - id
      - name
    properties:
      id:
        type: integer
        format: int64
      name:
        type: string
      tag:
        type: string
  newPet:
    type: object
    required:
      - name
    properties:
      id:
        type: integer
        format: int64
      name:
        type: string
      tag:
        type: string
  errorModel:
    type: object
    required:
      - code
      - message
    properties:
      code:
        type: integer
        format: int32
      message:
        type: string

[JFCote]

@gracekarina Sorry for the delay, things have been crazy a little bit. So here is an update. You solution is good but I made a slight modification. In Windows, I need to put ./ instead of /. It works with the basic Pet store samples. Final code looks like this:

swagger.yaml

swagger: '2.0'
info:
  version: '1.0.0'
  title: Swagger Petstore (Simple)
  description: A sample API that uses a petstore as an example to demonstrate features in the swagger-2.0 specification
  termsOfService: http://helloreverb.com/terms/
  contact:
    name: Swagger API team
    email: [e-mail]
    url: http://swagger.io
  license:
    name: MIT
    url: http://opensource.org/licenses/MIT
host: petstore.swagger.io
basePath: /api
schemes:
  - http
consumes:
  - application/json
produces:
  - application/json
paths:
  /pets:
    get:
      description: Returns all pets from the system that the user has access to
      operationId: findPets
      produces:
        - application/json
        - application/xml
        - text/xml
        - text/html
      parameters:
        - name: tags
          in: query
          description: tags to filter by
          required: false
          type: array
          items:
            type: string
          collectionFormat: csv
        - name: limit
          in: query
          description: maximum number of results to return
          required: false
          type: integer
          format: int32
      responses:
        '200':
          description: pet response
          schema:
            type: array
            items:
              $ref: './definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: './definitions.yaml#/definitions/errorModel'
    post:
      description: Creates a new pet in the store.  Duplicates are allowed
      operationId: addPet
      produces:
        - application/json
      parameters:
        - name: pet
          in: body
          description: Pet to add to the store
          required: true
          schema:
            $ref: './definitions.yaml#/definitions/newPet'
      responses:
        '200':
          description: pet response
          schema:
            $ref: './definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: './definitions.yaml#/definitions/errorModel'
  /pets/{id}:
    get:
      description: Returns a user based on a single ID, if the user does not have access to the pet
      operationId: findPetById
      produces:
        - application/json
        - application/xml
        - text/xml
        - text/html
      parameters:
        - name: id
          in: path
          description: ID of pet to fetch
          required: true
          type: integer
          format: int64
      responses:
        '200':
          description: pet response
          schema:
            $ref: './definitions.yaml#/definitions/pet'
        default:
          description: unexpected error
          schema:
            $ref: './definitions.yaml#/definitions/errorModel'
    delete:
      description: deletes a single pet based on the ID supplied
      operationId: deletePet
      parameters:
        - name: id
          in: path
          description: ID of pet to delete
          required: true
          type: integer
          format: int64
      responses:
        '204':
          description: pet deleted
        default:
          description: unexpected error
          schema:
            $ref: './definitions.yaml#/definitions/errorModel'

definitions.yaml

definitions:
  pet:
    type: object
    required:
      - id
      - name
    properties:
      id:
        type: integer
        format: int64
      name:
        type: string
      tag:
        type: string
  newPet:
    type: object
    required:
      - name
    properties:
      id:
        type: integer
        format: int64
      name:
        type: string
      tag:
        type: string
  errorModel:
    type: object
    required:
      - code
      - message
      - pet
    properties:
      code:
        type: integer
        format: int32
      message:
        type: string

If I change the errorModel to this (pointer to another model), I get an error:

  errorModel:
    type: object
    required:
      - code
      - message
      - pet
    properties:
      code:
        type: integer
        format: int32
      message:
        type: string
      pet:
        $ref: "#/newPet"

Error I receive:

Exception in thread "main" java.lang.RuntimeException: Could not find newPet in contents of ./definitions.yaml
        at io.swagger.parser.ResolverCache.loadRef(ResolverCache.java:134)
        at io.swagger.parser.processors.ExternalRefProcessor.processRefToExternalDefinition(ExternalRefProcessor.java:34)
        at io.swagger.parser.processors.ExternalRefProcessor.processRefProperty(ExternalRefProcessor.java:119)
        at io.swagger.parser.processors.ExternalRefProcessor.processRefToExternalDefinition(ExternalRefProcessor.java:83)
        at io.swagger.parser.processors.PropertyProcessor.processRefProperty(PropertyProcessor.java:34)
        at io.swagger.parser.processors.PropertyProcessor.processProperty(PropertyProcessor.java:21)
        at io.swagger.parser.processors.ResponseProcessor.processResponse(ResponseProcessor.java:21)
        at io.swagger.parser.processors.OperationProcessor.processOperation(OperationProcessor.java:45)
        at io.swagger.parser.processors.PathsProcessor.processPaths(PathsProcessor.java:101)
        at io.swagger.parser.SwaggerResolver.resolve(SwaggerResolver.java:50)
        at io.swagger.parser.SwaggerParser.read(SwaggerParser.java:67)
        at io.swagger.codegen.config.CodegenConfigurator.toClientOptInput(CodegenConfigurator.java:431)
        at io.swagger.codegen.cmd.Generate.run(Generate.java:283)
        at io.swagger.codegen.SwaggerCodegen.main(SwaggerCodegen.java:35)

Is this a but or am I doing something wrong again?

Thanks!

[JFCote]

@gracekarina Oh nice! I’m pretty busy today but next week I will try it with my real spec to see if this is working.

Thank you very much for looking into this! I’ll keep you posted