implement "cdn ls" via CommandLineParser

src/console/CommandTree/DefaultCommandTree.cs

@@ -26,6 +26,7 @@ namespace Shamir.Console
                 {
                     if (command.Name == args[0])
                     {
+                        command.Initialize(args[1..]);
                         return command;
                     }
                 }

src/console/CommandTree/DefaultHelpTextCommand.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Immutable;
 using System.Threading.Tasks;
 
@@ -15,7 +16,11 @@ namespace Shamir.Console
 
         public IImmutableStack<ICommandTree> Path { get; }
 
-        public ValueTask<int> ExecuteAsync()
+        public void Initialize(ReadOnlySpan<string> args)
+        {
+        }
+        
+        public ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider)
         {
             System.Console.Error.WriteLine(GetHelpText());
             return ValueTask.FromResult(1); // TODO: const

src/console/CommandTree/ICommand.cs

@@ -1,9 +1,11 @@
+using System;
 using System.Threading.Tasks;
 
 namespace Shamir.Console
 {
     public interface ICommand : IOperationsNode
     {
-        ValueTask<int> ExecuteAsync();
+        void Initialize(ReadOnlySpan<string> args);
+        ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider);
     }
 }

src/console/Commands/Cdn/StorageLsCommand.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Immutable;
+using System.Threading.Tasks;
+using Azure.Storage.Blobs;
+using CommandLine;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Shamir.Console
+{
+    public abstract class ParsedArgumentsCommand<TOptions> : ICommand
+    {
+        public abstract string Name { get; }
+        public abstract string Description { get; }
+        public ImmutableArray<string> Arguments { get; private set; }
+
+        public void Initialize(ReadOnlySpan<string> args)
+        {
+            var array = ImmutableArray.CreateBuilder<string>(args.Length);
+            foreach (var arg in args)
+            {
+                array.Add(arg);
+            }
+            Arguments = array.MoveToImmutable();
+        }
+
+        public async ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider)
+        {
+            using var parser = serviceProvider.GetRequiredService<Parser>();
+            var result = parser.ParseArguments<TOptions>(Arguments);
+            return await result.MapResult(
+                options => ExecuteAsync(serviceProvider, options),
+                errors => ValueTask.FromResult(1)
+            );
+        }
+
+        public abstract ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider, TOptions options);
+    }
+
+    public class StorageLsOptions
+    {
+        [Option("connection-string", Required = false)]
+        public string? ConnectionString { get; set; }
+
+        [Value(0)]
+        public string? ContainerName { get; set; }
+    }
+
+    public sealed class StorageLsCommand : ParsedArgumentsCommand<StorageLsOptions>
+    {
+        public override string Name => "ls";
+
+        public override string Description => "List files in an Azure Storage account.";
+
+        public override async ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider, StorageLsOptions options)
+        {
+            var connectionString = options.ConnectionString ?? Environment.GetEnvironmentVariable("AZURE_CONNECTION_STRING");
+            
+            if (options.ContainerName is null)
+            {
+                var client = new BlobServiceClient(connectionString);
+                await foreach (var container in client.GetBlobContainersAsync())
+                {
+                    System.Console.WriteLine(container.Name);
+                }
+            }
+            else
+            {
+                var client = new BlobContainerClient(connectionString, options.ContainerName);
+
+                await foreach (var blob in client.GetBlobsAsync())
+                {
+                    System.Console.Write(options.ContainerName);
+                    System.Console.Write('/');
+                    System.Console.WriteLine(blob.Name);
+                }
+            }
+
+            return 0;
+        }
+    }
+}

src/console/Program.cs

@@ -1,5 +1,7 @@
 using System.Collections.Immutable;
 using System.Threading.Tasks;
+using CommandLine;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Shamir.Console
 {
@@ -7,19 +9,29 @@ namespace Shamir.Console
     {
         public static async Task<int> Main(string[] args)
         {
+            await using var serviceProvider = new ServiceCollection()
+                .AddTransient<Parser>(sp => new Parser(with => with.EnableDashDash = true))
+                .BuildServiceProvider();
+
             var tree = new DefaultCommandTree(
                 "shamir",
                 "command-line multitool",
                 ImmutableArray.Create<ICommandTree>(
-
+                    new DefaultCommandTree(
-                ),
+                        "cdn",
+                        "Browse and add new data to a CDN backed by Azure Storage",
+                        ImmutableArray<ICommandTree>.Empty,
                         ImmutableArray.Create<ICommand>(
-
+                            new StorageLsCommand()
-                )
+                        ))
+                ),
+                ImmutableArray<ICommand>.Empty
             );
 
             var command = tree.FindCommand(args);
-            return await command.ExecuteAsync();
+
+            using var scope = serviceProvider.CreateScope();
+            return await command.ExecuteAsync(scope.ServiceProvider);
         }
     }
 }

src/console/shamir.csproj

@@ -9,7 +9,9 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Azure.Storage.Blobs" Version="12.10.0" />
     <PackageReference Include="CommandLineParser" Version="2.8.0" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="5.0.2" />
   </ItemGroup>
 
 </Project>

tests/console.tests/CommandTreeTests.cs

@@ -83,7 +83,9 @@ Commands:
 
             public string Name { get; }
             public string Description { get; }
-            public ValueTask<int> ExecuteAsync() => ValueTask.FromResult(0);
+
+            public void Initialize(ReadOnlySpan<string> args) { }
+            public ValueTask<int> ExecuteAsync(IServiceProvider serviceProvider) => ValueTask.FromResult(0);
         }
     }
 }