Add MapPatch overloads to routing

[davidfowl]

Background and Motivation

Today we have shortcuts for the most common HTTP methods for route handling (GET, POST, PUT, DELETE) but we don't have PATCH (or OPTIONS, TRACE, HEAD). We should add MapPatch to the set of methods we support. MapPatch is also interesting because people can now write custom binders in minimal APIs to handle the body. Today calling MapMethods(..) is the workaround (https://github.com/felipeoriani/MinimalBlogApi/blob/83732f1785a4c01a63ccf6909ca2a8190c63b4c9/Program.cs#L118) but it's kinda gross.

Proposed API

namespace Microsoft.AspNetCore.Builder
{
    public static class DelegateEndpointRouteBuilderExtensions
    {
+       public static DelegateEndpointConventionBuilder MapPatch(this IEndpointRouteBuilder endpoints, string pattern, Delegate handler);
    }
}

Usage Examples

app.MapPatch("/patch", (Patch<Model> patch)
{
      return patch.Changes;
});

Risks

Low.

Questions:

• Do we also add RequestDelegate overloads here?

[pranavkm]

API approved. We discussed adding MapHead along with this, but it typically appears in a place where GET and HEAD need to be supported together. MapMethods is what we would recommend in that case. We should also add the RequestDelegate overload as part of this change:

namespace Microsoft.AspNetCore.Builder
{
    public static class DelegateEndpointRouteBuilderExtensions
    {
+       public static DelegateEndpointConventionBuilder MapPatch(this IEndpointRouteBuilder endpoints, string pattern, Delegate handler);
    }
}

namespace Microsoft.AspNetCore.Builder
{
    public static class EndpointRouteBuilderExtensions
    {
+        public static IEndpointConventionBuilder MapPatch(this IEndpointRouteBuilder endpoints, string pattern, RequestDelegate requestDelegate)
    }
}

[noamyogev84]

hey @pranavkm , i'll be happy to tackle this one 🎉