ASP.NET Core Minimal API中如何通过HttpRequestMessage获取路由名称

我希望测试ASP.NET Core Minimal API的WebApplication路由功能，请问如何根据给定的HttpRequestMessage获取对应的路由名称？

初始代码示例 #

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddRouting().Configure<RouteOptions>(options => {});
var app = builder.Build();

app.MapGet("/hello", () => "Hello!").WithName(RouteNames.Hello);
app.MapGet("/world", () => "World!").WithName(RouteNames.World);

//app.Run();

var request = new HttpRequestMessage(HttpMethod.Get, "/world");
var routeName = GetRouteName(app, request);
Console.WriteLine($"routeName: {routeName}");

string? GetRouteName(WebApplication app, HttpRequestMessage request)
{
    return null; // TODO: Implement
}

static class RouteNames
{
    public const string Hello = "Hello";
    public const string World = "World";
}

目前官方暂未提供直接通过HttpRequestMessage获取路由名称的原生API。

可行实现方案 #

可以通过Microsoft.AspNetCore.TestHost包来实现，首先添加包引用：

<PackageReference Include="Microsoft.AspNetCore.TestHost" Version="7.0.5" />

完整可行代码如下：

using Microsoft.AspNetCore.TestHost;
using System.Diagnostics;

var host = new HostBuilder()
    .ConfigureWebHost(webHost => webHost.UseTestServer().Configure(app =>
    {
        app.UseRouting();
        app.Use((context, next) =>
        {
            if (context.GetEndpoint() is Endpoint endpoint)
            {
                var endpointName = endpoint.Metadata.GetMetadata<IEndpointNameMetadata>()?.EndpointName;
                if (endpointName != null)
                {
                    context.Response.Headers.Add(TagKeys.EndpointName, endpointName);
                }
            }
            return next();
        });
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapGet("/hello", () => "Hello!").WithName(RouteNames.Hello);
            endpoints.MapGet("/world", () => "World!").WithName(RouteNames.World);
        });
    })
    .ConfigureServices(services =>
    {
        services.AddRouting().Configure<RouteOptions>(routeOptions => { });
    }
    )
    ).Build();
host.Start();
var httpClient = host.GetTestClient();

await PrintEndpointName(httpClient, new HttpRequestMessage(HttpMethod.Get, "/"));
await PrintEndpointName(httpClient, new HttpRequestMessage(HttpMethod.Get, "/hello"));
await PrintEndpointName(httpClient, new HttpRequestMessage(HttpMethod.Get, "/world"));

async Task PrintEndpointName(HttpClient httpClient, HttpRequestMessage request)
{
    var httpResponse = await httpClient.SendAsync(request);
    IEnumerable<string>? headers;
    httpResponse.Headers.TryGetValues(TagKeys.EndpointName, out headers);
    var endpointName = headers?.FirstOrDefault();
    Debug.WriteLine($"{((int)httpResponse.StatusCode)} {endpointName}");
}

static class RouteNames
{
    public const string Hello = "Hello";
    public const string World = "World";
}

static class TagKeys
{
    public const string EndpointName = "endpoint.name";
}

内容的提问来源于stack exchange，提问作者Cameron Taggart