Merge pull request #764 from jonsequitur/improve-AddService

Improve BindingContext.AddService

Author: jonsequitur

src/System.CommandLine.Hosting/HostingExtensions.cs

@@ -41,7 +41,7 @@ public static CommandLineBuilder UseHost(this CommandLineBuilder builder,
 
                 using (var host = hostBuilder.Build())
                 {
-                    invocation.BindingContext.AddService(typeof(IHost), () => host);
+                    invocation.BindingContext.AddService(typeof(IHost), _ => host);
 
                     await host.StartAsync();
 

src/System.CommandLine/Binding/BindingContext.cs

@@ -46,7 +46,7 @@ public IConsole Console
 
         internal ServiceProvider ServiceProvider { get; }
 
-        public void AddService(Type serviceType, Func<object> factory)
+        public void AddService(Type serviceType, Func<IServiceProvider, object> factory)
         {
             if (serviceType == null)
             {

src/System.CommandLine/Invocation/InvocationContext.cs

@@ -19,8 +19,8 @@ public InvocationContext(
             IConsole console = null)
         {
             BindingContext = new BindingContext(parseResult, console);
-            BindingContext.ServiceProvider.AddService(GetCancellationToken);
-            BindingContext.ServiceProvider.AddService(() => this);
+            BindingContext.ServiceProvider.AddService(_ => GetCancellationToken());
+            BindingContext.ServiceProvider.AddService(_ => this);
         }
 
         public IConsole Console => BindingContext.Console;

src/System.CommandLine/Invocation/ServiceProvider.cs

@@ -13,33 +13,33 @@ internal class ServiceProvider : IServiceProvider
     {
         private readonly BindingContext _bindingContext;
 
-        private readonly Dictionary<Type, Func<object>> _services;
+        private readonly Dictionary<Type, Func<IServiceProvider, object>> _services;
 
         public ServiceProvider(BindingContext bindingContext)
         {
             _bindingContext = bindingContext ?? throw new ArgumentNullException(nameof(bindingContext));
 
-            _services = new Dictionary<Type, Func<object>>
+            _services = new Dictionary<Type, Func<IServiceProvider, object>>
                         {
-                            [typeof(ParseResult)] = () => _bindingContext.ParseResult,
-                            [typeof(IConsole)] = () => _bindingContext.Console,
-                            [typeof(CancellationToken)] = () => CancellationToken.None,
-                            [typeof(IHelpBuilder)] = () => _bindingContext.ParseResult.Parser.Configuration.HelpBuilderFactory(_bindingContext),
-                            [typeof(BindingContext)] = () => _bindingContext
+                            [typeof(ParseResult)] = _ => _bindingContext.ParseResult,
+                            [typeof(IConsole)] = _ => _bindingContext.Console,
+                            [typeof(CancellationToken)] = _ => CancellationToken.None,
+                            [typeof(IHelpBuilder)] = _ => _bindingContext.ParseResult.Parser.Configuration.HelpBuilderFactory(_bindingContext),
+                            [typeof(BindingContext)] = _ => _bindingContext
                         };
         }
 
-        public void AddService<T>(Func<T> factory) => _services[typeof(T)] = () => factory();
+        public void AddService<T>(Func<IServiceProvider, T> factory) => _services[typeof(T)] = p => factory(p);
 
-        public void AddService(Type serviceType, Func<object> factory) => _services[serviceType] = factory;
+        public void AddService(Type serviceType, Func<IServiceProvider, object> factory) => _services[serviceType] = factory;
 
         public IReadOnlyCollection<Type> AvailableServiceTypes => _services.Keys;
 
         public object GetService(Type serviceType)
         {
             if (_services.TryGetValue(serviceType, out var factory))
             {
-                return factory();
+                return factory(this);
             }
 
             return null;