Optional parameters in the path generate invalid swagger

Strange as it may be, if you have a controller method

[Route("{id}")]
public HttpResponseMessage Get(long? id = null)
{
 ...
}

This generates invalid swagger json since the parameter comes out with “required”:false

{
    "swagger": "2.0",
    "info": {
        "version": "v1",
        "title": "WebApplication3"
    },
    "host": "localhost:58728",
    "schemes": [
        "http"
    ],
    "paths": {
        "/api/books/{id}": {
            "get": {
                "tags": [
                    "Books"
                ],
                "operationId": "Books_Get",
                "consumes": [],
                "produces": [
                    "application/json",
                    "text/json",
                    "application/xml",
                    "text/xml"
                ],
                "parameters": [
                    {
                        "name": "id",
                        "in": "path",
                        "required": false,
                        "type": "integer",
                        "format": "int64"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK",
                        "schema": {
                            "$ref": "#/definitions/Object"
                        }
                    }
                },
                "deprecated": false
            }
        }
    },
    "definitions": {
        "Object": {
            "type": "object",
            "properties": {}
        }
    }
}

According to http://swagger.io/v2/schema.json a “pathParameterSubSchema” is only allowed to have “required”:true

I realize that the method is a little strange as its not actually callable without specifying the {id} as part of the URL, however the actual code was a bit more complicated. This was a simplified example to demonstrate the bug.

[kwaazaar]

Ok, thats a pity. Yet you could also generate multiple routes/endpoints: one for each variant. In my example that would be three of them. Or I could do that myself by specifying all variants in the webapi controller, which I will do for now.

[domaindrivendev]

Swagger is a specification (see http://swagger.io/specification/). Swashbuckle generates Swagger. The specification DOES NOT support optional parameters in “path”.