AutoRest- Duplicate operation detected

I was trying to use AutoRest to generate a client SDK for one of my API’s. This turned out not to be the success I was hoping for.

Yesterday I explained that I got into trouble because an OperationId was missing. But after adding it, it still didn’t work. Instead I got the following error message:

Duplicate operation detected

Here was the API controller I was using:

	[Route("generate")]
	public class GenerationController : ControllerBase
	{
	[HttpPost("upload/file/{targetFileName}.{extension}")]
	public IActionResult Upload(IFormFile templateFile, IFormFile xmlFile, string targetFileName, string extension)
	{
	}
	[HttpPost("upload/uri/{targetFileName}.{extension}")]
	public async Task<IActionResult> Upload([FromQuery] Uri template, IFormFile xmlFile, string targetFileName, string extension)
	{
	}
	}

view raw GenerationController.cs hosted with ❤ by GitHub

AutoRest uses the OpenAPI generated through Swashbuckle. When I took  a look at the OpenAPI file, I noticed that indeed the same OperationId was used:

	"/generate/upload/file/{targetFileName}.{extension}": {
	"post": {
	"tags": [
	"Generation"
	],
	"operationId": "upload"
	},
	"/generate/upload/uri/{targetFileName}.{extension}": {
	"post": {
	"tags": [
	"Generation"
	],
	"operationId": "upload"
	}
	},

view raw swagger.json hosted with ❤ by GitHub

This is because I was using the ActionName as the OperationId. As I have multiple Action methods with the same name they all result in the same OperationIe

To fix it, you can do 2 things:

• Using the [SwaggerOperation] attribute
• Using the Name property on the Http attribute ([HttpGet], [HttpPost],…)

Using the [SwaggerOperation] attribute

By adding a [SwaggerOperation] attribute to the controller action method, you can control the generated OperationId:

	[HttpPost("upload/file/{targetFileName}.{extension}")]
	[SwaggerOperation("GenerateFromUploadedFile")]
	public IActionResult Upload(IFormFile templateFile, IFormFile xmlFile, string targetFileName, string extension)
	{
	}

view raw SwaggerOperation.cs hosted with ❤ by GitHub

Using the Name property

An alternative solution is to use the Name property on the HTTP routing attributes:

	[HttpPost("upload/file/{targetFileName}.{extension}", Name="GenerateFromUploadedFile")]
	public IActionResult Upload(IFormFile templateFile, IFormFile xmlFile, string targetFileName, string extension)
	{
	}

view raw NameProperty.cs hosted with ❤ by GitHub