Rename HostingAction to HostingWrappingAction and remove BindingHandler dependency and extension methods

Author: fredrikhr

src/System.CommandLine.Hosting/HostingExtensions.cs

@@ -1,60 +1,11 @@
-using System.CommandLine.Binding;
-using System.CommandLine.Invocation;
-using System.CommandLine.NamingConventionBinder;
-using CommandHandler = System.CommandLine.NamingConventionBinder.CommandHandler;
+#nullable enable
 
-using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
-using Microsoft.Extensions.Options;
 
 namespace System.CommandLine.Hosting
 {
     public static class HostingExtensions
     {
-        public static CommandLineConfiguration UseHost(
-            this CommandLineConfiguration config,
-            Func<string[], IHostBuilder> hostBuilderFactory,
-            Action<IHostBuilder> configureHost = null)
-        {
-            if (config.RootCommand is RootCommand root)
-            {
-                root.Add(new Directive(HostingAction.HostingDirectiveName));
-            }
-
-            HostingAction.SetHandlers(config.RootCommand, hostBuilderFactory, configureHost);
-
-            return config;
-        }
-
-        public static CommandLineConfiguration UseHost(
-            this CommandLineConfiguration config,
-            Action<IHostBuilder> configureHost = null
-        ) => UseHost(config, null, configureHost);
-
-        public static OptionsBuilder<TOptions> BindCommandLine<TOptions>(
-            this OptionsBuilder<TOptions> optionsBuilder)
-            where TOptions : class
-        {
-            if (optionsBuilder is null)
-                throw new ArgumentNullException(nameof(optionsBuilder));
-            return optionsBuilder.Configure<IServiceProvider>((opts, serviceProvider) =>
-            {
-                var modelBinder = serviceProvider
-                    .GetService<ModelBinder<TOptions>>()
-                    ?? new ModelBinder<TOptions>();
-                var bindingContext = serviceProvider.GetRequiredService<BindingContext>();
-                modelBinder.UpdateInstance(opts, bindingContext);
-            });
-        }
-
-        public static Command UseCommandHandler<THandler>(this Command command)
-            where THandler : CommandLineAction
-        {
-            command.Action = CommandHandler.Create(typeof(THandler).GetMethod(nameof(AsynchronousCommandLineAction.InvokeAsync)));
-
-            return command;
-        }
-
         public static ParseResult GetParseResult(this IHostBuilder hostBuilder)
         {
             _ = hostBuilder ?? throw new ArgumentNullException(nameof(hostBuilder));
@@ -76,12 +27,5 @@ public static ParseResult GetParseResult(this HostBuilderContext context)
 
             throw new InvalidOperationException("Host builder context has no command-line parse result registered to it.");
         }
-
-        public static IHost GetHost(this ParseResult parseResult)
-        {
-            _ = parseResult ?? throw new ArgumentNullException(paramName: nameof(parseResult));
-            var hostModelBinder = new ModelBinder<IHost>();
-            return (IHost)hostModelBinder.CreateInstance(parseResult.GetBindingContext());
-        }
     }
 }

src/System.CommandLine.Hosting/HostingAction.cs renamed to src/System.CommandLine.Hosting/HostingWrappingAction.cs

@@ -1,7 +1,5 @@
 using System.Collections.Generic;
-using System.CommandLine.Binding;
 using System.CommandLine.Invocation;
-using System.CommandLine.NamingConventionBinder;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -12,7 +10,7 @@
 namespace System.CommandLine.Hosting
 {
     // It's a wrapper, that configures the host, starts it and then runs the actual action.
-    internal sealed class HostingAction : BindingHandler
+    internal sealed class HostingWrappingAction : AsynchronousCommandLineAction
     {
         internal const string HostingDirectiveName = "config";
 
@@ -22,7 +20,7 @@ internal sealed class HostingAction : BindingHandler
 
         internal static void SetHandlers(Command command, Func<string[], IHostBuilder> hostBuilderFactory, Action<IHostBuilder> configureHost)
         {
-            command.Action = new HostingAction(hostBuilderFactory, configureHost, (AsynchronousCommandLineAction)command.Action);
+            command.Action = new HostingWrappingAction(hostBuilderFactory, configureHost, (AsynchronousCommandLineAction)command.Action);
             command.TreatUnmatchedTokensAsErrors = false; // to pass unmatched Tokens to host builder factory
 
             foreach (Command subCommand in command.Subcommands)
@@ -31,18 +29,13 @@ internal static void SetHandlers(Command command, Func<string[], IHostBuilder> h
             }
         }
 
-        private HostingAction(Func<string[], IHostBuilder> hostBuilderFactory, Action<IHostBuilder> configureHost, AsynchronousCommandLineAction actualAction)
+        private HostingWrappingAction(Func<string[], IHostBuilder> hostBuilderFactory, Action<IHostBuilder> configureHost, AsynchronousCommandLineAction actualAction)
         {
             _hostBuilderFactory = hostBuilderFactory;
             _configureHost = configureHost;
             _actualAction = actualAction;
         }
 
-        public override BindingContext GetBindingContext(ParseResult parseResult)
-            => _actualAction is BindingHandler bindingHandler
-                   ? bindingHandler.GetBindingContext(parseResult)
-                   : base.GetBindingContext(parseResult);
-
         public override async Task<int> InvokeAsync(ParseResult parseResult, CancellationToken cancellationToken = default)
         {
             var argsRemaining = parseResult.UnmatchedTokens;
@@ -76,35 +69,16 @@ public override async Task<int> InvokeAsync(ParseResult parseResult, Cancellatio
                 }
             }
 
-            var bindingContext = GetBindingContext(parseResult);
-            int registeredBefore = 0;
-            hostBuilder.ConfigureServices(services =>
+            hostBuilder.ConfigureServices(static (context, services) =>
             {
+                var parseResult = context.GetParseResult();
                 services.AddSingleton(parseResult);
-                services.AddSingleton(bindingContext);
-
-                registeredBefore = services.Count;
             });
 
-            if (_configureHost is not null)
-            {
-                _configureHost.Invoke(hostBuilder);
-
-                hostBuilder.ConfigureServices(services =>
-                {
-                    // "_configureHost" just registered types that might be needed in BindingContext
-                    for (int i = registeredBefore; i < services.Count; i++)
-                    {
-                        Type captured = services[i].ServiceType;
-                        bindingContext.AddService(captured, c => c.GetService<IHost>().Services.GetService(captured));
-                    }
-                });
-            }
+            _configureHost?.Invoke(hostBuilder);
 
             using var host = hostBuilder.Build();
 
-            bindingContext.AddService(typeof(IHost), _ => host);
-
             await host.StartAsync(cancellationToken);
 
             try

src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
+    <LangVersion>12</LangVersion>
     <IsPackable>true</IsPackable>
     <TargetFrameworks>netstandard2.0;netstandard2.1;$(TargetFrameworkForNETSDK)</TargetFrameworks>
     <Description>This package provides support for using System.CommandLine with Microsoft.Extensions.Hosting.</Description>
@@ -20,7 +21,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\System.CommandLine.NamingConventionBinder\System.CommandLine.NamingConventionBinder.csproj" />
     <ProjectReference Include="..\System.CommandLine\System.CommandLine.csproj" />
   </ItemGroup>