Unsure on the generated request for 204 (and by extension 201) requests, with no content

[JSparshottO2]

So I have a situation where in an openApi spec I'm provided has a 204, and a default configured. The request generated by Kiota includes an Accept header with the default content type in it, whereas a 204 has no content configured as an empty response type, from the spec.

The upshot of this, is the default is an "error" response with an error app type. when this is provided to the endpoint expecting a 204, it complains that the Accept header is invalid and an acceptable Accept header would be application/json

I have exampled this with the below:

{
	"openapi": "3.0.1",
	"info": {
        "title": "My Api",
        "description": "An example spec with a generational issue",
        "version": "v1",
        "x-framework": {
            "name": "blablabla"
        }
    },
    "servers": [{
            "url": "https://my.exampledomain.com/awesome/api"
        }
    ],
    "security": [{
            "OAuth_1.0_authorization": []
        }
    ],
	"paths": {
		"/data": {
			"post": {
                "tags": ["data"],
                "summary": "Insert data.",
                "requestBody": {
                    "description": "Request body.",
                    "content": {
                        "application/json": {
                            "schema": {
                                "$ref": "#/components/schemas/data"
                            }
                        }
                    },
                    "required": true
                },
                "responses": {
                    "204": {
                        "description": "Inserted record."
                    },
                    "default": {
                        "description": "Error response.",
                        "content": {
                            "application/custom-error": {
                                "schema": {
                                    "$ref": "#/components/schemas/error"
                                }
                            }
                        }
                    }
                }
            }
		}
	},
    "components": {
        "schemas": {
			"error": {
                "type": "object",
                "properties": {
                    "message": {
                        "title": "Error reason",
                        "type": "string",
                        "readOnly": true
                    }
				}
			},
			"data": {
                "type": "object",
                "properties": {
                    "stuff": {
                        "title": "Some Data",
                        "type": "string"
                    },
                    "numberedStuff": {
                        "title": "Some number",
                        "type": "integer",
						"format": "int64"
                    }
				}
			}
		}
	}
}

where if you run the default kiota generation on it:

kiota generate --openapi exampleSpec.json --output \Kiota --language CSharp

it has the following in the generated builder for the Data object:

requestInfo.Headers.TryAdd("Accept", "application/custom-error");

Mainly, I'm trying to work out if I either: Go to the provider of this OpenAPI spec and say that they either need to provide the acceptable "Accept" headers for a 204. OR they broaden their acceptable Accept headers to also allow the error type in the Accept. OR is this a Kiota issue and it shouldn't really be looking for Accept headers when generating for a 204 (or 201), contentless response?

[baywet]

Hi @JSparshottO2
Thank you for using kiota and for reaching out.

In kiota, default should only be used for error responses (generating the exception types)

kiota/src/Kiota.Builder/KiotaBuilder.cs

Line 1250 in 6c20342

if (operation.Responses.TryGetValue("default", out var defaultResponse) && defaultResponse.GetResponseSchema(config.StructuredMimeTypes) is { } errorSchema)

I believe this case is what you're going through.

kiota/src/Kiota.Builder/KiotaBuilder.cs

Line 1449 in 6c20342

(null, _) => operation.Responses!

The conditions line 1450 and 1455 are wrong, they should also exclude: default, 4XX and 5XX

Is this something you'd like to submit a pull request for provided some guidance?

[JSparshottO2]

hi @baywet thanks for having a look at this! I'm not that fussed about raising a PR for it, unless it's the type of small change you'd like the contribution on. I can raise an Issue for it though if you'd like?

[baywet]

we'd very much like a contribution for that if you're up to it! Sure, you can go ahead and create an issue for this.

[JSparshottO2]

Okay i've raised the issue now.