Add ParameterInfo argument to BindAsync by halter73 · Pull Request #35791 · dotnet/aspnetcore

halter73 · 2021-08-26T20:16:25Z

Before:

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/webhook", (CloudEvent cloudEvent) =>
{
    redis.Publish(cloudEvent);
});

app.Run();

public class CloudEvent
{
    public static async ValueTask<object?> BindAsync(HttpContext context)
    {
        return await CloudEventParser.ReadEventAsync(context);
    }
}

After:

public class CloudEvent
{
    public static async ValueTask<CloudEvent?> BindAsync(HttpContext context, ParameterInfo parameter)
    {
        return await CloudEventParser.ReadEventAsync(context, parameter.Name);
    }
}

This adds a ParameterInfo as a second parameter and changes the return type from ValueTask<object?> to ValueTask<T> (and/or ValueTask<T?> for reference types).

Static methods with close-but-different signatures (e.g. ValueTask<CloudEvent?> BindAsync(HttpContext context) or ValueTask<object?> BindAsync(HttpContext context, ParameterInfo parameter) will not be matched.

Note: If CloudEvent is a struct, the return type must be ValueTask<CloudEventStruct> not ValueTask<ClouldEventStruct?>. I do not think this is a major issue since if CloudEven was a struct we already wouldn't call BindAsync given a CloudEventStruct? parameter. When we add support for nullable struct BindAsync parameter, we should also look for a nullable-returning BindAsync method.

public struct CloudEventStruct
{
	// This will NOT be matched because it returns a nullable struct!!!
    public static async ValueTask<CloudEventStruct?> BindAsync(HttpContext context, ParameterInfo parameter)
    {
        return await CloudEventParser.ReadEventAsync(context, parameter.Name);
    }
}

Fixes #35748

src/Shared/TryParseMethodCache.cs

src/Http/Http.Extensions/test/TryParseMethodCacheTests.cs

src/Http/Http.Extensions/src/RequestDelegateFactory.cs

src/Shared/TryParseMethodCache.cs

halter73 · 2021-08-26T20:48:50Z

/backport to release/6.0-rc1

github-actions · 2021-08-26T20:49:04Z

Started backporting to release/6.0-rc1: https://github.com/dotnet/aspnetcore/actions/runs/1171970183

src/Shared/TryParseMethodCache.cs

halter73 added 2 commits August 26, 2021 12:13

Add ParameterInfo argument to BindAsync(HttpContext)

27f18d5

Return ValueTask<{type}> instead of ValueTask<object?> from BindAsync

e35945b

halter73 requested review from BrennanConroy, Pilchie and Tratcher as code owners August 26, 2021 20:16

halter73 requested review from DamianEdwards, davidfowl and rafikiassumani-msft August 26, 2021 20:17