ASP.NET Core route template constraints

Program.cs

using System;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;
using Microsoft.AspNetCore.Routing.Patterns;
using Microsoft.AspNetCore.Routing.Template;
using Microsoft.Extensions.DependencyInjection;

var provider = new ServiceCollection().AddRouting(_ => {}).BuildServiceProvider();
var templateBinderFactory = provider.GetRequiredService<TemplateBinderFactory>();

const string pattern = "/users/{action:regex(^(get|create)$)}";

var routeTemplate = TemplateParser.Parse(pattern);
var defaults = new RouteValueDictionary();
#if false
var templateBinder = templateBinderFactory.Create(routeTemplate, defaults);
#else
var routePattern = RoutePatternFactory.Parse(pattern);
var templateBinder = templateBinderFactory.Create(routePattern);
#endif
var matcher = new TemplateMatcher(routeTemplate, defaults);

foreach (var path in new[] { "/users/get", "/users/create", "/users/xyz", "/orders/get" })
{
    var context = new DefaultHttpContext { Request = { Path = path } };
    var values = new RouteValueDictionary();
    var match = matcher.TryMatch(path, values);
    var success = templateBinder.TryProcessConstraints(context, values, out _, out _);
    Console.WriteLine($"{path} {(success ? "✅" : "❌")} ({match})");
}

TemplateConstraints.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <FrameworkReference Include="Microsoft.AspNetCore.App" />
  </ItemGroup>

</Project>