cleanup: obsolete async API that doesn't have Async in the name

Author: natemcmaster

docs/samples/custom-conventions/Program.cs

@@ -71,7 +71,7 @@ public void Apply(ConventionContext context)
                 }
 
                 // when this subcommand is selected, invoke the method on the model instance
-                cmd.OnExecute(async () =>
+                cmd.OnExecuteAsync(async cancellationToken =>
                 {
                     // get an instance of the model type from CommandLineApplication<TModel>
                     var modelInstance = context.ModelAccessor.GetModel();

docs/samples/helloworld-async/Program.cs

@@ -19,7 +19,7 @@ public static int Main(string[] args)
         var optionSubject = app.Option("-s|--subject <SUBJECT>", "The subject", CommandOptionType.SingleValue);
         var optionRepeat = app.Option<int>("-n|--count <N>", "Repeat", CommandOptionType.SingleValue);
 
-        app.OnExecute(async () =>
+        app.OnExecuteAsync(async cancellationToken =>
         {
             var subject = optionSubject.HasValue()
                 ? optionSubject.Value()
@@ -31,7 +31,7 @@ public static int Main(string[] args)
                 Console.Write($"Hello");
 
                 // This pause here is just for indication that some awaitable operation could happens here.
-                await Task.Delay(5000);
+                await Task.Delay(5000, cancellationToken);
                 Console.WriteLine($" {subject}!");
             }
         });

src/CommandLineUtils/CommandLineApplication.cs

@@ -668,13 +668,22 @@ private void AddArgument(CommandArgument argument)
         /// <param name="invoke"></param>
         public void OnExecute(Func<int> invoke)
         {
-            _action = _ => Task.FromResult(invoke());
+            _handler = _ => Task.FromResult(invoke());
         }
 
         /// <summary>
+        /// <para>
+        /// This method is obsolete and will be removed in a future version.
+        /// The recommended alternative is <see cref="OnExecuteAsync" />.
+        /// </para>
+        /// <para>
         /// Defines an asynchronous callback.
+        /// </para>
         /// </summary>
         /// <param name="invoke"></param>
+        [Obsolete("This method is obsolete and will be removed in a future version. " +
+                  "The recommended replacement is .OnExecuteAsync()")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public void OnExecute(Func<Task<int>> invoke) => OnExecuteAsync(_ => invoke());
 
         /// <summary>

src/CommandLineUtils/CommandLineApplicationExtensions.cs

@@ -3,8 +3,10 @@
 // This file has been modified from the original form. See Notice.txt in the project root for more information.
 
 using System;
+using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;
 using System.Reflection;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace McMaster.Extensions.CommandLineUtils
@@ -95,14 +97,37 @@ public static CommandOption VerboseOption(this CommandLineApplication app, strin
             => app.Option(template, "Show verbose output", CommandOptionType.NoValue, inherited: true);
 
         /// <summary>
-        /// Sets <see cref="CommandLineApplication.Invoke"/> with a return code of <c>0</c>.
+        /// <para>
+        /// This method is obsolete and will be removed in a future version.
+        /// The recommended alternative is <see cref="OnExecuteAsync" />.
+        /// </para>
+        /// <para>
+        /// Sets an async handler with a return code of <c>0</c>.
+        /// </para>
         /// </summary>
         /// <param name="app"></param>
         /// <param name="action">An asynchronous action to invoke when the ocmmand is selected..</param>
+        [Obsolete("This method is obsolete and will be removed in a future version. " +
+                  "The recommended replacement is .OnExecuteAsync()")]
+        [EditorBrowsable(EditorBrowsableState.Never)]
         public static void OnExecute(this CommandLineApplication app, Func<Task> action)
-            => app.OnExecute(async () =>
+        {
+            app.OnExecute(async () =>
+                       {
+                           await action();
+                           return 0;
+                       });
+        }
+
+        /// <summary>
+        /// Sets an async handler with a return code of <c>0</c>.
+        /// </summary>
+        /// <param name="app"></param>
+        /// <param name="action">An asynchronous action to invoke when the ocmmand is selected..</param>
+        public static void OnExecuteAsync(this CommandLineApplication app, Func<CancellationToken, Task> action)
+            => app.OnExecuteAsync(async ct =>
             {
-                await action();
+                await action(ct);
                 return 0;
             });