Client generation in NSwagStudio exceptions

[tndata]

When I try to generate a C# .NET Core3 client using the NSwagStudio (13.1.6.0) the following OpenAPI document generates exception

https://leksaker.starweb.se/api/v2/openapi.json

I have imported it into SwaggerHub without any errors.

I have also saved it as Yaml here: http://download.edument.se/openapi.yaml (from swaggerhub and http://online.swagger.io/)

Any hint on how I can debug this?

The exception I get is:

System.InvalidOperationException: Error while rendering Liquid template CSharp/Client.Class:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
---> System.InvalidOperationException: Sequence contains more than one matching element

[haiduc32]

Same problem here. Traced the source of the exception to referencing the same response in multiple places, in your case that's: 400":{"$ref":"#/components/responses/BadRequest"},
BadReqeuest is referenced multiple times.
Doesn't make any sense why it behaves that way. Waiting for someone to look at this issue.

[RicoSuter]

Do we have a stacktrace or something?

[haiduc32]

Stack trace from running NSwagStudio (latest version) with the document provided in the first post:

System.InvalidOperationException: Error while rendering Liquid template CSharp/Client.Class:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: Sequence contains more than one matching element

Runtime: Default
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate)
at NSwag.OpenApiResponse.IsBinary(OpenApiOperation operation)
at NSwag.CodeGeneration.Models.ResponseModelBase.get_CheckChunkedStatusCode()
--- End of inner exception stack trace ---
at DotLiquid.Context.HandleError(Exception ex)
at DotLiquid.Block.RenderAll(List1 list, Context context, TextWriter result) at DotLiquid.Document.Render(Context context, TextWriter result) at DotLiquid.Template.RenderInternal(TextWriter result, RenderParameters parameters) at DotLiquid.Template.Render(TextWriter writer, RenderParameters parameters) at DotLiquid.Template.Render(RenderParameters parameters) at NJsonSchema.CodeGeneration.DefaultTemplateFactory.LiquidTemplate.Render() ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: Sequence contains more than one matching element at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate) at NSwag.OpenApiResponse.IsBinary(OpenApiOperation operation) at NSwag.CodeGeneration.Models.ResponseModelBase.get_CheckChunkedStatusCode() --- End of inner exception stack trace --- at DotLiquid.Context.HandleError(Exception ex) at DotLiquid.Block.RenderAll(List1 list, Context context, TextWriter result)
at DotLiquid.Document.Render(Context context, TextWriter result)
at DotLiquid.Template.RenderInternal(TextWriter result, RenderParameters parameters)
at DotLiquid.Template.Render(TextWriter writer, RenderParameters parameters)
at DotLiquid.Template.Render(RenderParameters parameters)
at NJsonSchema.CodeGeneration.DefaultTemplateFactory.LiquidTemplate.Render()
--- End of inner exception stack trace ---
at NJsonSchema.CodeGeneration.DefaultTemplateFactory.LiquidTemplate.Render()
at NSwag.CodeGeneration.CSharp.CSharpClientGenerator.d__8.MoveNext()
at System.Collections.Generic.List1.InsertRange(Int32 index, IEnumerable1 collection)
at NSwag.CodeGeneration.ClientGeneratorBase3.GenerateAllClientTypes() at NSwag.CodeGeneration.ClientGeneratorBase3.GenerateFile(ClientGeneratorOutputType outputType)
at NSwag.Commands.CodeGeneration.SwaggerToCSharpClientCommand.<b__83_0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NSwag.Commands.CodeGeneration.SwaggerToCSharpClientCommand.d__83.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NSwag.Commands.CodeGeneration.SwaggerToCSharpClientCommand.d__82.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NSwag.Commands.NSwagDocument.d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NSwag.Commands.Document.ExecuteDocumentCommand.d__9.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NSwag.Commands.Document.ExecuteDocumentCommand.d__8.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NConsole.CommandLineProcessor.d__12.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NConsole.CommandLineProcessor.d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at NConsole.CommandLineProcessor.Process(String[] args, Object input)
at NSwag.Commands.NSwagCommandProcessor.Process(String[] args)

[i-sinister]

NSwagStudio 13.2.2.0 fails to generate client for following spec:

openapi: '3.0.0'
paths:
  /bugs:
    get:
      summary: Returns list on NSwagStudio bugs
      responses:
        '200':
          $ref: '#/components/responses/NSwagStudioBug'
        '400':
          $ref: '#/components/responses/NSwagStudioBug'
components:
  responses:
    NSwagStudioBug:
      description: List of NSwagStudio bugs
      content:
        application/json:
          schema:
            type: array
            items:
              $ref: '#/components/schemas/NSwagStudioBug'
  schemas:
    NSwagStudioBug:
      description: Describes NSwagStudio bug
      type: object
      required:
        - description
      properties:
        description:
          description: Bug description
          type: string
      example:
        description: https://github.com/RicoSuter/NSwag/issues/2545

Error as in previous comment. The reason is using the same multiple response for different codes.

[haiduc32]

I've hit this bug again today (forgot about it) and I can see I already commented..

Is anyone working on it, or can I take a shot at fixing it?

[jeremyVignelles]

If there's no open PR, you can assume nobody is working on it.
Thanks 👍

[RicoSuter]

So the same response object is in resolved multiple times in the ActualResponses?

[haiduc32]

Apologies for the late reply.
Just for the record - yes, that is correct, Operation.ActualResponses will contain one item for each response (different http codes) but with the same r.Value if your responses have the same "$ref". Which is correct (IMHO). So the solution was to change the code to use the "Any" Linq method, as to the best of my understanding this bit of code just checks that the current response is not 204. I changed it to check that there is at least one response that is not 204, so that the response can be binary.