Invalid json-schema objects are generated

[ershov-konst]

Description

If an object contains two or more properties with the same complex type, generated json-schema object is invalid.

Example

openapi.json

{
  "swagger": "2.0",
  "info": {
    "title": "Test API",
    "version": "{{version}}"
  },
  ...
  "paths": {
    "/foo/api": {
      "get": {
        "summary": "GET /foo/api",
        "description": "GET /foo/api",
        "operationId": "GET--foo-api",
        "responses": {
          "200": {
            "description": "",
            "schema": {
              "$ref": "#/definitions/TestResponse"
            }
          }
        }
      }
    }
  },
  "definitions": {
    "TestResponse": {
      "type": "object",
      "properties": {
        "a": {
          "$ref": "#/definitions/CommonDefinition"
        },
        "b": {
          "$ref": "#/definitions/CommonDefinition"
        }
      }
    },
    "CommonDefinition": {
      "type": "object",
      "properties": {
        "foo": {
          "type": "string"
        }
      }
    }
  }
}

After compilation we receive following json-scheme object

{
  type: "object",
  properties: { 
    a: {
      type: "object",
      properties: { 
        foo: { 
          type: "string" 
        } 
      },
      $id: "default_CommonDefinition"
    }, 
    b: {
      type: "object",
      properties: { 
        foo: { 
          type: "string" 
        } 
      },
      $id: "default_CommonDefinition"
    }
  },
  $id: "default_TestResponse"
}

The problem is using the $id keyword that identifies a schema resource.

If you try to validate the object described below using ajv package, you will receive the following exception

Error: reference "#default_CommonDefinition" resolves to more than one schema