Short circuit attribute

[JamesNK]

Is there an existing issue for this?

• [X] I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

The short circuit feature only has extension methods for adding the required metadata to endpoints. Should there be an attribute? That would allow MVC actions and gRPC methods to support short circuiting.

For example,

public class MonitoringController
{
    [ShortCircuit]
    [HttpGet("/status")]
    public ActionResult GetStatus()
    {
        // ...
    }
}

Brought up in YouTube video: https://youtu.be/rXdwX2X4-gw?t=422

Note that a short-circuited MVC action would still execute filters, and a gRPC method would still execute interceptors.

Describe the solution you'd like

• Change internal ShortCircuitMetadata to an interface. (optional)
• Change current metadata to an attribute and make public (implement the interface if present)

Additional context

No response

[mitchdenny]

Given the intention of this wouldn't it be better to just encourage people to use the minimal version of the API?

[Kahbazi]

+1 On adding ShortCircuitAttribute. As long as the metadata is internal, frameworks like YARP can not add have short circuited routes.

[Tratcher]

Given the intention of this wouldn't it be better to just encourage people to use the minimal version of the API?

Controllers (and proxies 😆) are a lot more expensive than minimal, it's unclear how much relative cost an MVC endpoint would save with this attribute, and if making it available would be misleading. That said, the inconsistency is also confusing, they may legitimately have an expensive middleware to skip.

[fvoronin]

I'm interested in doing this. Can I take a look and submit a PR on that issue?

[ghost]

Thank you for submitting this for API review. This will be reviewed by @dotnet/aspnet-api-review at the next meeting of the ASP.NET Core API Review group. Please ensure you take a look at the API review process documentation and ensure that:

• The PR contains changes to the reference-assembly that describe the API change. Or, you have included a snippet of reference-assembly-style code that illustrates the API change.
• The PR describes the impact to users, both positive (useful new APIs) and negative (breaking changes).
• Someone is assigned to "champion" this change in the meeting, and they understand the impact and design of the change.

[halter73]

API Review Notes:

• It's a little surprising there was no public metadata type to begin with.
• It does seem like it could be useful for non-minimal endpoints.

API Approved!

namespace Microsoft.AspNetCore.Routing.ShortCircuit;

+ public sealed class ShortCircuitAttribute : Attribute, IShortCircuitMetadata
+ {
+    public ShortCircuitAttribute();
+    public ShortCircuitAttribute(int statusCode);
+
+    public int? StatusCode { get; }
+ }

+ public interface IShortCircuitMetadata
+ {
+    int? StatusCode { get; }
+ }

[danirzv]

If anyone else is not working on it, im interested to work it out, may i send a PR?

[fvoronin]

@danirzv, PR already exists https://github.com/dotnet/aspnetcore/pull/52571

[fvoronin]

API Approved!

namespace Microsoft.AspNetCore.Routing.ShortCircuit;

+ public sealed class ShortCircuitAttribute : Attribute, IShortCircuitMetadata
+ {
+    public ShortCircuitAttribute();
+    public ShortCircuitAttribute(int statusCode);
+
+    public int? StatusCode { get; }
+ }

+ public interface IShortCircuitMetadata
+ {
+    int? StatusCode { get; }
+ }

@halter73, sorry for long pause.

It seems to me that there are some issues with the ambiguity of attribute behaviour when there is a public constructor with parameter

public ShortCircuitAttribute(int statusCode);

For example, how should an application behave, with a controller like this:

public class TestController : ControllerBase
{
    [ShortCircuit(500)]
    public ActionResult Index()
    {
        if (foo)
            return new UnauthorizedResult();

        if (bar)
            return new BadRequestResult();

        return new OkResult();
    }
}

The statusCode specified in the ShortCircuit attribute does not match any of those returned from the method.

Would it still be better to make the constructor with the statusCode parameter as internal?

public sealed class ShortCircuitAttribute : Attribute, IShortCircuitMetadata
{
   public ShortCircuitAttribute();
-    public ShortCircuitAttribute(int statusCode);
+    internal ShortCircuitAttribute(int statusCode);

   public int? StatusCode { get; }
}

P.S. I'm work on it #52571