Multiple Precondition failed annotation using swashbuckle - asp.net-web-api

Question

I'm using swashbuckle to document my web api project and I cannot add multiple responses for precondition failed cases, swagger only shows the last one.
/// <response code="200">OK</response>
/// <response code="401">Unauthorized</response>
/// <response code="400">BadRequest</response>
/// <response code="412">ErrorCode = 1... </response>
/// <response code="412">ErrorCode = 2... </response>
/// <response code="412">ErrorCode = 3... </response>
Swashbuckle generates something like:
{
...
"responses": {
"200": {
"description": "OK"
},
"400": {
"description": "BadRequest"
},
"401": {
"description": "Unauthorized"
},
"412": {
"description": "ErrorCode = 3..."
}
}
...
}
Where I would like to see:
{
...
"412": {
"description": "ErrorCode = 1..."
},
"412": {
"description": "ErrorCode = 2..."
},
"412": {
"description": "ErrorCode = 3..."
}
}
Any thoughts about it?
Thanks in advance

Answer 1

What you are trying to achieve is not possible with Swashbuckle because it is not compliant with the Open API specification (aka Swagger). The responses object contains a list of possible responses. Each response has a name and a response object. The name can be default or a HTTP status code. According to the spec of a responses object there can be only one response object per status code:
Any HTTP status code can be used as the property name (one property per HTTP status code). Describes the expected response for that HTTP status code.
That being said, I doubt whether it is correct to add additional error codes to a 412 response. A conditional request might not reach your server in case a proxy server already knows the conditions won't be matched.