using Microsoft.Extensions.CommandLineUtils for blazor-cli

src/Microsoft.AspNetCore.Blazor.Cli/Commands/ServeCommand.cs

@@ -0,0 +1,21 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.CommandLineUtils;
+using System;
+using System.Diagnostics;
+using System.Text.RegularExpressions;
+
+namespace Microsoft.AspNetCore.Blazor.Cli.Commands
+{
+    class ServeCommand
+    {
+        public static void Command(CommandLineApplication command)
+        {
+            var remainingArgs = command.RemainingArguments.ToArray();
+
+            Server.Program.BuildWebHost(remainingArgs).Run();
+        }
+    }
+}

src/Microsoft.AspNetCore.Blazor.Cli/Microsoft.AspNetCore.Blazor.Cli.csproj

@@ -11,6 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.CommandLineUtils" Version="1.1.1" />
     <PackageReference Include="Microsoft.AspNetCore" Version="$(AspNetCorePackageVersion)" />
     <PackageReference Include="Microsoft.AspNetCore.ResponseCompression" Version="$(AspNetCorePackageVersion)" />
   </ItemGroup>

src/Microsoft.AspNetCore.Blazor.Cli/Program.cs

@@ -4,6 +4,8 @@
 using Microsoft.AspNetCore.Hosting;
 using System;
 using System.Linq;
+using Microsoft.Extensions.CommandLineUtils;
+using Microsoft.AspNetCore.Blazor.Cli.Commands;
 
 namespace Microsoft.AspNetCore.Blazor.Cli
 {
@@ -11,22 +13,22 @@ namespace Microsoft.AspNetCore.Blazor.Cli
     {
         static int Main(string[] args)
         {
-            if (args.Length == 0)
+            var app = new CommandLineApplication
             {
-                Console.WriteLine("Usage: dotnet blazor <command>");
+                Name = "blazor-cli"
-                return 1;
+            };
+            app.HelpOption("-?|-h|--help");
+
+            app.Command("serve", ServeCommand.Command);
+
+            if (args.Length > 0)
+            {
+                return app.Execute(args);
             }
-
+            else
-            var command = args[0];
-            var remainingArgs = args.Skip(1).ToArray();
-
-            switch (command.ToLowerInvariant())
             {
-                case "serve":
+                app.ShowHelp();
-                    Server.Program.BuildWebHost(remainingArgs).Run();
+                return 0;
-                    return 0;
-                default:
-                    throw new InvalidOperationException($"Unknown command: {command}");
             }
         }
     }