Revert "provide more flexible mechanism for directive handlers: possi…

…bility to pass next handler and invoke it or not"

This reverts commit fc987d4.

src/System.CommandLine.ApiCompatibility.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt

@@ -108,10 +108,10 @@ System.CommandLine
     public static System.Void Write(this IConsole console, System.String value)
     public static System.Void WriteLine(this IConsole console, System.String value)
   public class Directive : Symbol
-    .ctor(System.String name, System.String description = null, System.Action<System.CommandLine.Invocation.InvocationContext,ICommandHandler> syncHandler = null, System.Func<System.CommandLine.Invocation.InvocationContext,ICommandHandler,System.Threading.CancellationToken,System.Threading.Tasks.Task> asyncHandler = null)
+    .ctor(System.String name, System.String description = null, System.Action<System.CommandLine.Invocation.InvocationContext> syncHandler = null, System.Func<System.CommandLine.Invocation.InvocationContext,System.Threading.CancellationToken,System.Threading.Tasks.Task> asyncHandler = null)
     public System.Collections.Generic.IEnumerable<System.CommandLine.Completions.CompletionItem> GetCompletions(System.CommandLine.Completions.CompletionContext context)
-    public System.Void SetAsynchronousHandler(System.Func<System.CommandLine.Invocation.InvocationContext,ICommandHandler,System.Threading.CancellationToken,System.Threading.Tasks.Task> handler)
-    public System.Void SetSynchronousHandler(System.Action<System.CommandLine.Invocation.InvocationContext,ICommandHandler> handler)
+    public System.Void SetAsynchronousHandler(System.Func<System.CommandLine.Invocation.InvocationContext,System.Threading.CancellationToken,System.Threading.Tasks.Task> handler)
+    public System.Void SetSynchronousHandler(System.Action<System.CommandLine.Invocation.InvocationContext> handler)
   public class EnvironmentVariablesDirective : Directive
     .ctor()
   public static class Handler

src/System.CommandLine.Tests/DirectiveTests.cs

@@ -2,9 +2,7 @@
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
-using System.Threading.Tasks;
 using FluentAssertions;
 using Xunit;
 
@@ -139,50 +137,6 @@ public void When_directives_are_not_enabled_they_are_treated_as_regular_tokens()
                   .BeEquivalentTo("[hello]");
         }
 
-        [Theory]
-        [InlineData(false)]
-        [InlineData(true)]
-        public async Task Directive_can_restore_the_state_after_running_continuation(bool async)
-        {
-            const string plCulture = "pl-PL", enUsCulture = "en-US";
-            const string envVarName = "uniqueName", envVarValue = "just";
-
-            var before = CultureInfo.CurrentUICulture;
-
-            try
-            {
-                CultureInfo.CurrentUICulture = new(enUsCulture);
-
-                bool invoked = false;
-                Option<bool> option = new("-a");
-                RootCommand root = new() { option };
-                CommandLineBuilder builder = new(root);
-                builder.Directives.Add(new EnvironmentVariablesDirective());
-                builder.Directives.Add(new CultureDirective());
-                root.SetHandler(ctx =>
-                {
-                    invoked = true;
-                    CultureInfo.CurrentUICulture.Name.Should().Be(plCulture);
-                    Environment.GetEnvironmentVariable(envVarName).Should().Be(envVarValue);
-                });
-
-                if (async)
-                {
-                    await builder.Build().InvokeAsync($"[culture:{plCulture}] [env:{envVarName}={envVarValue}]");
-                }
-                else
-                {
-                    builder.Build().Invoke($"[culture:{plCulture}] [env:{envVarName}={envVarValue}]");
-                }
-
-                invoked.Should().BeTrue();
-            }
-            finally
-            {
-                CultureInfo.CurrentUICulture = before;
-            }
-        }
-
         private static ParseResult Parse(Option option, Directive directive, string commandLine)
         {
             RootCommand root = new() { option };
@@ -191,47 +145,5 @@ private static ParseResult Parse(Option option, Directive directive, string comm
 
             return root.Parse(commandLine, builder.Build());
         }
-
-        private sealed class CultureDirective : Directive
-        {
-            public CultureDirective() : base("culture")
-            {
-                SetSynchronousHandler((ctx, next) =>
-                {
-                    CultureInfo cultureBefore = CultureInfo.CurrentUICulture;
-
-                    try
-                    {
-                        string cultureName = ctx.ParseResult.FindResultFor(this).Values.Single();
-
-                        CultureInfo.CurrentUICulture = new CultureInfo(cultureName);
-
-                        next?.Invoke(ctx);
-                    }
-                    finally
-                    {
-                        CultureInfo.CurrentUICulture = cultureBefore;
-                    }
-                });
-                SetAsynchronousHandler(async (ctx, next, ct) =>
-                {
-                    CultureInfo cultureBefore = CultureInfo.CurrentUICulture;
-
-                    try
-                    {
-                        string cultureName = ctx.ParseResult.FindResultFor(this).Values.Single();
-
-                        CultureInfo.CurrentUICulture = new CultureInfo(cultureName);
-
-                        await next?.InvokeAsync(ctx, ct);
-                    }
-                    finally
-                    {
-                        CultureInfo.CurrentUICulture = cultureBefore;
-                    }
-                });
-            }
-        }
-
     }
 }

src/System.CommandLine/Directive.cs

@@ -3,6 +3,7 @@
 using System.CommandLine.Invocation;
 using System.Threading.Tasks;
 using System.Threading;
+using System.CommandLine.Parsing;
 
 namespace System.CommandLine
 {
@@ -17,22 +18,17 @@ namespace System.CommandLine
     /// </summary>
     public class Directive : Symbol
     {
-        internal Action<InvocationContext, ICommandHandler?>? SyncHandler;
-        internal Func<InvocationContext, ICommandHandler?, CancellationToken, Task>? AsyncHandler;
-
         /// <summary>
         /// Initializes a new instance of the Directive class.
         /// </summary>
         /// <param name="name">The name of the directive. It can't contain whitespaces.</param>
         /// <param name="description">The description of the directive, shown in help.</param>
         /// <param name="syncHandler">The synchronous action that is invoked when directive is parsed.</param>
         /// <param name="asyncHandler">The asynchronous action that is invoked when directive is parsed.</param>
-        /// <remarks>The second argument of both handlers is next handler than can be invoked.
-        /// Example: a custom directive might just change current culture and run actual command afterwards.</remarks>
         public Directive(string name, 
             string? description = null, 
-            Action<InvocationContext, ICommandHandler?>? syncHandler = null,
-            Func<InvocationContext, ICommandHandler?, CancellationToken, Task>? asyncHandler = null)
+            Action<InvocationContext>? syncHandler = null,
+            Func<InvocationContext, CancellationToken, Task>? asyncHandler = null)
         {
             if (string.IsNullOrWhiteSpace(name))
             {
@@ -50,17 +46,37 @@ public Directive(string name,
             Name = name;
             Description = description;
 
-            SyncHandler = syncHandler;
-            AsyncHandler = asyncHandler;
+            if (syncHandler is not null)
+            {
+                SetSynchronousHandler(syncHandler);
+            }
+            else if (asyncHandler is not null)
+            {
+                SetAsynchronousHandler(asyncHandler);
+            }
         }
 
-        internal bool HasHandler => SyncHandler != null || AsyncHandler != null;
+        public void SetAsynchronousHandler(Func<InvocationContext, CancellationToken, Task> handler)
+        {
+            if (handler is null)
+            {
+                throw new ArgumentNullException(nameof(handler));
+            }
 
-        public void SetAsynchronousHandler(Func<InvocationContext, ICommandHandler?, CancellationToken, Task> handler)
-            => AsyncHandler = handler ?? throw new ArgumentNullException(nameof(handler));
+            Handler = new AnonymousCommandHandler(handler);
+        }
+
+        public void SetSynchronousHandler(Action<InvocationContext> handler)
+        {
+            if (handler is null)
+            {
+                throw new ArgumentNullException(nameof(handler));
+            }
+
+            Handler = new AnonymousCommandHandler(handler);
+        }
 
-        public void SetSynchronousHandler(Action<InvocationContext, ICommandHandler?> handler)
-            => SyncHandler = handler ?? throw new ArgumentNullException(nameof(handler));
+        internal ICommandHandler? Handler { get; private set; }
 
         private protected override string DefaultName => throw new NotImplementedException();
 

src/System.CommandLine/EnvironmentVariablesDirective.cs

@@ -1,5 +1,5 @@
-using System.CommandLine.Parsing;
-using System.Threading.Tasks;
+using System.CommandLine.Invocation;
+using System.CommandLine.Parsing;
 
 namespace System.CommandLine
 {
@@ -10,28 +10,12 @@ public sealed class EnvironmentVariablesDirective : Directive
     {
         public EnvironmentVariablesDirective() : base("env")
         {
-            SetSynchronousHandler((context, next) =>
-            {
-                SetEnvVars(context.ParseResult);
-
-                next?.Invoke(context);
-            });
-            SetAsynchronousHandler((context, next, cancellationToken) =>
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return Task.FromCanceled(cancellationToken);
-                }
-
-                SetEnvVars(context.ParseResult);
-
-                return next?.InvokeAsync(context, cancellationToken) ?? Task.CompletedTask;
-            });
+            SetSynchronousHandler(SyncHandler);
         }
 
-        private void SetEnvVars(ParseResult parseResult)
+        private void SyncHandler(InvocationContext context)
         {
-            DirectiveResult directiveResult = parseResult.FindResultFor(this)!;
+            DirectiveResult directiveResult = context.ParseResult.FindResultFor(this)!;
 
             for (int i = 0; i < directiveResult.Values.Count; i++)
             {
@@ -51,6 +35,9 @@ private void SetEnvVars(ParseResult parseResult)
                     }
                 }
             }
+
+            // we need a cleaner, more flexible and intuitive way of continuing the execution
+            context.ParseResult.CommandResult.Command.Handler?.Invoke(context);
         }
     }
 }

src/System.CommandLine/ParseDirective.cs

@@ -1,7 +1,6 @@
 using System.CommandLine.Invocation;
 using System.CommandLine.IO;
 using System.CommandLine.Parsing;
-using System.Threading.Tasks;
 
 namespace System.CommandLine
 {
@@ -13,32 +12,17 @@ public sealed class ParseDirective : Directive
         /// <param name="errorExitCode">If the parse result contains errors, this exit code will be used when the process exits.</param>
         public ParseDirective(int errorExitCode = 1) : base("parse")
         {
+            SetSynchronousHandler(SyncHandler);
             ErrorExitCode = errorExitCode;
-
-            SetSynchronousHandler(PrintDiagramAndQuit);
-            SetAsynchronousHandler((context, next, cancellationToken) =>
-            {
-                if (cancellationToken.IsCancellationRequested)
-                {
-                    return Task.FromCanceled(cancellationToken);
-                }
-
-                PrintDiagramAndQuit(context, null);
-
-                return Task.CompletedTask;
-            });
         }
 
         internal int ErrorExitCode { get; }
 
-        private void PrintDiagramAndQuit(InvocationContext context, ICommandHandler? next)
+        private void SyncHandler(InvocationContext context)
         {
             var parseResult = context.ParseResult;
             context.Console.Out.WriteLine(parseResult.Diagram());
             context.ExitCode = parseResult.Errors.Count == 0 ? 0 : ErrorExitCode;
-
-            // parse directive has a precedence over --help and --version and any command
-            // we don't invoke next here.
         }
     }
 }