Improve error messages for implicit and explicit FromBody attribute in Minimal API #35086

[rafikiassumani-msft]

Improve error messages for implicit and explicit FromBody attribute in Minimal API #35086

PR Description

This a draft PR to start the conversation on a possible solution for error messages when :

1. The Minimal MapPost/Put/Patch/etc.. has two body parameters either explicitly or implicitly. This would address a case where one of the body parameter may be a service that the user forgot to register with the DI container and binding fails to resolve.

Example:

  app.MapPost("/car", ([FromBody] SampleDTO sampleDTO, IUserRepo userRepo) => $"{sampleDTO.Name}");

In the example above, the code changes will keep track of all the request parameters and provide an error message telling the user which parameters we could successfully infer which ones fail. It also adds the parameter source (From Query String, Route, Services, etc.)

  Unhandled exception. System.InvalidOperationException: Failure to infer one or more parameters. Below is the list of parameters we found:

Parameter          Source

sampleDTO  Body Attribute
userRepo We failed to infer this parameter. Did you forget to inject it as a Service?

   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateArguments(ParameterInfo[] parameters, FactoryContext factoryContext) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 209
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, RequestDelegateFactoryOptions options, Expression targetExpression) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 170
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.Create(Delegate action, RequestDelegateFactoryOptions options) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 89
   at Microsoft.AspNetCore.Builder.MinimalActionEndpointRouteBuilderExtensions.Map(IEndpointRouteBuilder endpoints, RoutePattern pattern, Delegate action) in C:\Users\rassumani\bench\aspnetcore\src\Http\Routing\src\Builder\MinimalActionEndpointRouteBuilderExtensions.cs:line 173
   at Microsoft.AspNetCore.Builder.MinimalActionEndpointRouteBuilderExtensions.MapMethods(IEndpointRouteBuilder endpoints, String pattern, IEnumerable`1 httpMethods, Delegate action) in C:\Users\rassumani\bench\aspnetcore\src\Http\Routing\src\Builder\MinimalActionEndpointRouteBuilderExtensions.cs:line 109
   at Microsoft.AspNetCore.Builder.MinimalActionEndpointRouteBuilderExtensions.MapPost(IEndpointRouteBuilder endpoints, String pattern, Delegate action) in C:\Users\rassumani\bench\aspnetcore\src\Http\Routing\src\Builder\MinimalActionEndpointRouteBuilderExtensions.cs:line 54

2. There is No content type and the content length is zero, however, there is still an implicit FromBody parameter that we need to bind like in the case below:

 app.MapGet("/test/{id}", (int id, SampleDTO sampleDTO) => $"id is {id}  - {sampleDTO.Name}");

We will read the body httpContext.Request.ReadFromJsonAsync(bodyType) and throw an exception in CreateContentTypeError method.

Exception:

  System.InvalidOperationException: We failed to infer or bind 'SampleDTO' parameter. Was this a Service parameter that you forgot to register ?
   at Microsoft.AspNetCore.Http.HttpRequestJsonExtensions.ReadFromJsonAsync(HttpRequest request, Type type, JsonSerializerOptions options, CancellationToken cancellationToken) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\HttpRequestJsonExtensions.cs:line 129
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.<>c__DisplayClass42_0.<<HandleRequestBodyAndCompileRequestDelegate>b__0>d.MoveNext() in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 517
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger) in C:\Users\rassumani\bench\aspnetcore\src\Http\Routing\src\EndpointMiddleware.cs:line 79
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context) in C:\Users\rassumani\bench\aspnetcore\src\Middleware\Diagnostics\src\DeveloperExceptionPage\DeveloperExceptionPageMiddleware.cs:line 94

Fixes #35086

[halter73]

I think we should split this into two PRs. One for throwing for multiple from-body parameters during Create() and another for throwing for not finding a body when one is expected during the request.

[halter73]

Suggested change

	factoryContext.TrackedParameters.Add(parameter.Name!, "We failed to infer this parameter. Did you forget to inject it as a Service in the DI container?");
	factoryContext.TrackedParameters.Add(parameter.Name!, "UNKNOWN");

I think the following is a bit hard to read:

  Unhandled exception. System.InvalidOperationException: Failure to infer one or more parameters. Below is the list of parameters we found:

Parameter          Source

sampleDTO  Body Attribute
userRepo We failed to infer this parameter. Did you forget to inject it as a Service?

   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateArguments(ParameterInfo[] parameters, FactoryContext factoryContext) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 209
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, RequestDelegateFactoryOptions options, Expression targetExpression) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 170
   ...

This would be a bit better:

  Unhandled exception. System.InvalidOperationException: Failure to infer one or more parameters. Below is the list of parameters we found:

Parameter |            Source
----------+------------------
sampleDTO |  Body (Attribute)
userRepo  |            UNKOWN


Did you forget to inject the "UNKNOWN" parameters as a Service?


   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateArguments(ParameterInfo[] parameters, FactoryContext factoryContext) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 209
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, RequestDelegateFactoryOptions options, Expression targetExpression) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 170
   ...

Adding the | and - would require more than just the suggested fix of course but I think it will help. Can you show what this looks like on the developer exception page?

[halter73]

Also, do we get the same "Failure to infer one or more parameters." error when all the parameters have explicit attributes? If there actually are multiple [FromBody] attributes we should probably just continue saying that's not allowed instead of saying we couldn't infer the source.

[rafikiassumani-msft]

Do we have a logger formatter or console formatter in aspnetcore that I can use ?

[rafikiassumani-msft]

I am hoping an analyzer will prevent the double explicit [FromBody] right away.

[rafikiassumani-msft]

New formatting. Not perfect, visually readable.

Unhandled exception. System.InvalidOperationException: Failure to infer one or more parameters.
Below is the list of parameters that we found:

Parameter           |Source
---------------------------------------------------------------------------------
id                  | Route (Inferred)
dto                 | Body (Attribute)
dto1                | UNKNOWN
repo                | Service (Attribute)
repo1               | UNKNOWN


Did you forget to inject the "UNKNOWN" parameters as a Service?


   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateArguments(ParameterInfo[] parameters, FactoryContext factoryContext) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 196
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, RequestDelegateFactoryOptions options, Expression targetExpression) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 165
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.Create(Delegate action, RequestDelegateFactoryOptions options) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 84

[davidfowl]

"Did you mean to register the "UNKNOWN" parameters as a Service?"

[rafikiassumani-msft]

Unhandled exception. System.InvalidOperationException: Failure to infer one or more parameters.
Below is the list of parameters that we found:

Parameter           |Source
---------------------------------------------------------------------------------
id                  | Route (Inferred)
dto                 | Body (Attribute)
dto1                | UNKNOWN
repo                | Service (Attribute)
repo1               | UNKNOWN


Did you mean to register the "UNKNOWN" parameters as a Service?


   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateArguments(ParameterInfo[] parameters, FactoryContext factoryContext) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 196
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.CreateTargetableRequestDelegate(MethodInfo methodInfo, RequestDelegateFactoryOptions options, Expression targetExpression) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 165
   at Microsoft.AspNetCore.Http.RequestDelegateFactory.Create(Delegate action, RequestDelegateFactoryOptions options) in C:\Users\rassumani\bench\aspnetcore\src\Http\Http.Extensions\src\RequestDelegateFactory.cs:line 84

[captainsafia]

Great call to add a separate class for all the constants we're introducing here.

[davidfowl]

Super nit:

Suggested change

	if(factoryContext.HasMultipleBodyParameters)
	if (factoryContext.HasMultipleBodyParameters)

[davidfowl]

This isn't correct anymore. It's either route or query or either.