Nswag: Q: What are the rules to use nswag to avoid exceptions

[bhaidar]

Hello,
I have been using nswag from the command line for some time now. Today, out of a sudden, I started getting this error:

``` System.AggregateException: One or more errors occurred. ---> System.InvalidOperationException: Sequence contains more than one matching element at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate) at NSwag.CodeGeneration.TypeScript.Templates.RequestBodyTemplate.TransformText() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\RequestBodyTemplate.tt:line 2 at NSwag.CodeGeneration.TypeScript.Templates.AngularClientTemplate.TransformText() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\AngularClientTemplate.tt:line 50 at NSwag.CodeGeneration.TypeScript.Templates.AngularClientTemplate.Render() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\AngularClientTemplate.Extensions.cs:l ine 18 at NSwag.CodeGeneration.ClientGeneratorBase3.GenerateFile(SwaggerDocument document, ClientGeneratorOutputType type) in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration\ClientGeneratorBa
se.cs:line 90
at NSwag.Commands.SwaggerToTypeScriptClientCommand.<b__100_0>d.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 265
--- 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.SwaggerToTypeScriptClientCommand.d__100.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 256
--- 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.SwaggerToTypeScriptClientCommand.d__99.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 249
--- 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.NSwagDocumentBase.d__28.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\NSwagDocumentBase.cs:line 187
--- 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.ExecuteDocumentCommandBase.d__5.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommandBase.cs:
line 52
--- 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.ExecuteDocumentCommandBase.d__4.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommandBase.cs:line 39
--- 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() in C:\projects\nconsole\src\NConsole\CommandLineProcessor.cs:line 139
--- 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() in C:\projects\nconsole\src\NConsole\CommandLineProcessor.cs:line 107
--- End of inner exception stack trace ---
at System.Threading.Tasks.Task1.GetResultCore(Boolean waitCompletionNotification) at NSwag.Commands.NSwagCommandProcessor.Process(String[] args) in C:\Data\Projects\NSwag\src\NSwag.Commands\NSwagCommandProcessor.cs:line 59 ---> (Inner Exception #0) System.InvalidOperationException: Sequence contains more than one matching element at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate) at NSwag.CodeGeneration.TypeScript.Templates.RequestBodyTemplate.TransformText() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\RequestBodyTemplate.tt:line 2 at NSwag.CodeGeneration.TypeScript.Templates.AngularClientTemplate.TransformText() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\AngularClientTemplate.tt:line 50 at NSwag.CodeGeneration.TypeScript.Templates.AngularClientTemplate.Render() in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration.TypeScript\Templates\AngularClientTemplate.Extensions.cs:l ine 18 at NSwag.CodeGeneration.ClientGeneratorBase3.GenerateFile(SwaggerDocument document, ClientGeneratorOutputType type) in C:\Data\Projects\NSwag\src\NSwag.CodeGeneration\ClientGeneratorBa
se.cs:line 90
at NSwag.Commands.SwaggerToTypeScriptClientCommand.<b__100_0>d.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 265
--- 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.SwaggerToTypeScriptClientCommand.d__100.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 256
--- 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.SwaggerToTypeScriptClientCommand.d__99.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\SwaggerToTypeScriptClientCommand.cs:line 249
--- 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.NSwagDocumentBase.d__28.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\NSwagDocumentBase.cs:line 187
--- 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.ExecuteDocumentCommandBase.d__5.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommandBase.cs:
line 52
--- 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.ExecuteDocumentCommandBase.d__4.MoveNext() in C:\Data\Projects\NSwag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommandBase.cs:line 39
--- 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() in C:\projects\nconsole\src\NConsole\CommandLineProcessor.cs:line 139
--- 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() in C:\projects\nconsole\src\NConsole\CommandLineProcessor.cs:line 107<---
child_process.js:524
throw err;
^

Error: Command failed: "D:\Workspace...\node_modules\nswag\bin/binaries/full/nswag.exe" run
at checkExecSyncError (child_process.js:481:13)
at Object.execSync (child_process.js:521:13)
at Object. (D:\Workspace...\node_modules\nswag\bin\nswag.js:27:18)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
at run (bootstrap_node.js:390:7)
````

I looked thoroughly in my code and I cannot find any duplicate method names in my controllers.

Is there another reason for such an exception to happen? What if 2 different method names but with the same input type, does that cause any problem?

Thanks

[RicoSuter]

What version are you using? Did you just update NSwag? Can you provide a sample where this can be reproduced?

[bhaidar]

Thanks @RSuter for your feedback.
I am developing an ASP.NET Core (Full .NET) + Angular 2.

Everything was working fine until last night, dunno what happened and I started getting this error.

In the package,json, the version of NSWAG is: "nswag": "10.6.0"

Is there a way to debug the generation and see where it is breaking?

I can pass to you the json file. would that help? How should I pass it?

Thanks

[RicoSuter]

Have you tried to use the latest NSwag version (we are currently at v11.9.2)?
You can send it via email [email protected] if it shouldnt be public... Should be simple to fix (or troubleshoot) as soon as I know where the problem is...

[bhaidar]

@RSuter
Email sent. Thanks a lot for your swift feedback.

[RicoSuter]

Ok, the problem is "ApiServicesAppCheckDeletionHelperCheckIfEntityUsedPost" which has two Body parameters...

[bhaidar]

What does it mean to have 2 Body parameters?

Also, what if I don't want to generate TS code for this service, This should be an internal one for internal use, I don't know how it got generated...

[RicoSuter]

A HTTP response can only have one body payload (it's THE payload), so it is not allowed to have two body parameters. How are you generating the Swagger spec?

[bhaidar]

I understand. Everything was working fine until I added this helper service.

I use this command: "..\node_modules.bin\nswag" run

Based on a config file:
{ "swaggerGenerator": { "fromSwagger": { "url": "http://localhost:22742/swagger/v1/swagger.json", "output": null } }, "codeGenerators": { "swaggerToTypeScriptClient": { "className": "{controller}ServiceProxy", "moduleName": "", "namespace": "", "typeScriptVersion": 1.8, "template": "Angular", "promiseType": "Promise", "dateTimeType": "MomentJS", "nullValue": "Undefined", "generateClientClasses": true, "generateClientInterfaces": false, "generateOptionalParameters": false, "wrapDtoExceptions": false, "useTransformOptionsMethod": false, "useTransformResultMethod": false, "generateDtoTypes": true, "operationGenerationMode": "MultipleClientsFromPathSegments", "markOptionalProperties": false, "generateCloneMethod": false, "typeStyle": "Class", "extensionCode": "service.extensions.ts", "generateDefaultValues": true, "excludedTypeNames": [], "handleReferences": false, "generateConstructorInterface": true, "importRequiredTypes": true, "baseUrlTokenName": "API_BASE_URL", "output": "../src/shared/service-proxies/service-proxies.ts" }, "swaggerToCSharpClient": { "generateClientClasses": true, "generateClientInterfaces": false, "generateDtoTypes": true, "injectHttpClient": false, "disposeHttpClient": true, "generateExceptionClasses": true, "exceptionClass": "SwaggerException", "wrapDtoExceptions": true, "useHttpClientCreationMethod": false, "httpClientType": "System.Net.Http.HttpClient", "useHttpRequestMessageCreationMethod": false, "useBaseUrl": true, "generateSyncMethods": false, "clientClassAccessModifier": "public", "generateContractsOutput": false, "className": "{controller}Client", "namespace": "MyNamespace", "generateOptionalParameters": false, "requiredPropertiesMustBeDefined": true, "dateType": "System.DateTime", "dateTimeType": "System.DateTime", "timeType": "System.TimeSpan", "timeSpanType": "System.TimeSpan", "arrayType": "System.Collections.ObjectModel.ObservableCollection", "dictionaryType": "System.Collections.Generic.Dictionary", "classStyle": "Inpc", "operationGenerationMode": "MultipleClientsFromOperationId", "generateDefaultValues": true, "generateDataAnnotations": true, "excludedTypeNames": [], "wrapResponses": false, "generateResponseClasses": true, "responseClass": "SwaggerResponse", "handleReferences": false, "generateImmutableArrayProperties": false, "generateImmutableDictionaryProperties": false, "output": null }, "swaggerToCSharpController": { "className": "{controller}", "namespace": "MyNamespace", "additionalNamespaceUsages": [ "System.Web.Http" ], "generateOptionalParameters": false, "requiredPropertiesMustBeDefined": true, "dateType": "System.DateTime", "dateTimeType": "System.DateTime", "timeType": "System.TimeSpan", "timeSpanType": "System.TimeSpan", "arrayType": "System.Collections.Generic.IEnumerable", "dictionaryType": "System.Collections.Generic.Dictionary", "classStyle": "Inpc", "operationGenerationMode": "MultipleClientsFromOperationId", "generateDefaultValues": true, "generateDataAnnotations": true, "excludedTypeNames": [], "wrapResponses": false, "generateResponseClasses": true, "responseClass": "SwaggerResponse", "handleReferences": false, "generateImmutableArrayProperties": false, "generateImmutableDictionaryProperties": false, "output": null } } }

[RicoSuter]

Yes, the problem is the spec which is coming from "http://localhost:22742/swagger/v1/swagger.json", how is this generated?

The problem here: https://github.com/OAI/OpenAPI-Specification/blob/master/versions/2.0.md#fixed-fields-4

There can be one "body" parameter at most.

[bhaidar]

OK. the Swagger is configured in the Startup class of the ASP.NET Core (.NET full).

Is that what you are asking for?

services.AddSwaggerGen(options => { options.SwaggerDoc("v1", new Info { Title = "App API", Version = "v1" }); options.DocInclusionPredicate((docName, description) => true); });

// Enable middleware to serve generated Swagger as a JSON endpoint app.UseSwagger(); // Enable middleware to serve swagger-ui assets (HTML, JS, CSS etc.) app.UseSwaggerUI(options => { options.SwaggerEndpoint("/swagger/v1/swagger.json", "App API V1"); }); //URL: /swagger

[RicoSuter]

I see, you are using Swashbuckle to generate the swagger spec (and not NSwag). Somehow Swashbuckle generates two body params. You have to check its documentation or try NSwag’s swagger middleware (https://github.com/RSuter/NSwag/wiki/Middlewares)

[bhaidar]

Great. That was used in the framework I am using. I will see if I can switch. Thanks a lot for your time and quick response.

[bhaidar]

Would I be able to keep on using same client tool correct? The above middleware is just for json generation.

[RicoSuter]

What client tool ?

[bhaidar]

the nswag one that I run from inside command line to generate the TypeScript file.

[bhaidar]

I went to the referenced Url above, the middleware has the same Api like the one I am using "UseSwagger()". isn't it the same one?

[RicoSuter]

I think the url is the same (you canconfigure it) - the produced spec may differ (eg only one body param) but should be the same...

[bhaidar]

Thanks a lot. I will give it a try.

[RicoSuter]

Closed because it is a problem with Swashbuckle.