recurse function can recurse infinitely

Checklist

• Conversion: I have checked my source definition is valid OpenAPI 2.0

Detailed Description

When a valid OpenAPI 2.0 spec contains a definition which is self-referencing, the recurse function will go on forever (well, until the stack runs out) due to the fact that it has no maxDepth functionality. There needs to be some way like tracking maxDepth or recognizing that it is in an infinite recursion to break out.

Simple valid OpenAPI 2.0 spec illustrating issue:

{
  "info": {
    "title": "Example title",
    "description": "Example description.",
    "version": "v1"
  },
  "swagger": "2.0",
  "produces": [
    "application/xml",
    "application/json",
    "application/octet-stream",
    "text/plain"
  ],
  "host": "example.org",
  "basePath": "/example/v1",
  "schemes": [
    "https"
  ],
  "tags": [
    {
      "name": "examples",
      "description": "Operations about examples"
    }
  ],
  "paths": {
    "/examples": {
      "post": {
        "summary": "Create an example",
        "description": "Create an example using a POST request",
        "produces": [
          "application/json"
        ],
        "consumes": [
          "application/json"
        ],
        "parameters": [
          {
            "name": "Example",
            "in": "body",
            "required": true,
            "schema": {
              "$ref": "#/definitions/Example"
            }
          }
        ],
        "responses": {
          "201": {
            "description": "Created"
          },
          "400": {
            "description": "Bad Request"
          }
        },
        "tags": [
          "examples"
        ],
        "operationId": "postExample"
      }
    }
  },
  "definitions": {
    "Example": {
      "type": "object",
      "properties": {
        "id": {
          "type": "string"
        },
        "sub_examples": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/Example"
          }
        }
      },
      "required": [
        "id",
        "sub_examples"
      ],
      "description": "Create an example"
    }
  }
}

[jdmurphy]

@MikeRalphson that seems to have fixed the issue. Thank you.

[MikeRalphson]

I’ve added detection of already seen objects to the recursion which is done to limit request/response examples to that given in options.maxDepth. Could you let me know if v3.6.5 resolves this for you?