Add dotnet-add command

src/dotnet/Program.cs

@@ -24,6 +24,7 @@ using Microsoft.DotNet.Tools.Run;
 using Microsoft.DotNet.Tools.Test;
 using Microsoft.DotNet.Tools.VSTest;
 using NuGet.Frameworks;
+using Microsoft.DotNet.Tools.Add;
 
 namespace Microsoft.DotNet.Cli
 {
@@ -45,6 +46,7 @@ namespace Microsoft.DotNet.Cli
             ["run"] = RunCommand.Run,
             ["test"] = TestCommand.Run,
             ["vstest"] = VSTestCommand.Run,
+            ["add"] = AddCommand.Run,
         };
 
         public static int Main(string[] args)

src/dotnet/commands/dotnet-add/Program.cs

@@ -0,0 +1,68 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.Collections.Generic;
+using Microsoft.DotNet.Cli.CommandLine;
+using Microsoft.DotNet.Cli.Utils;
+using System;
+using System.IO;
+using System.Linq;
+using Microsoft.Build.Construction;
+using Microsoft.DotNet.ProjectJsonMigration;
+using NuGet.Frameworks;
+
+namespace Microsoft.DotNet.Tools.Add
+{
+    public class AddCommand
+    {
+        public const string CommandName = "dotnet-add";
+        public const string UsageText = @"Usage: dotnet add [command] [arguments]
+
+Arguments:
+  [command]             The command to execute
+  [arguments]           Arguments to pass to the command
+
+Commands:
+  p2p           Add project to project (p2p) reference to a project";
+
+        private static Dictionary<string, Func<string[], int>> s_builtIns = new Dictionary<string, Func<string[], int>>
+        {
+            ["p2p"] = null,
+        };
+
+        public static int Run(string[] args)
+        {
+            DebugHelper.HandleDebugSwitch(ref args);
+
+            if (args.Length == 0 || args[0] == "--help" || args[0] == "-h")
+            {
+                Reporter.Output.WriteLine(UsageText);
+                return 1;
+            }
+
+            if (args[0].StartsWith("-"))
+            {
+                Reporter.Error.WriteLine($"Unknown option: {args[0]}");
+                Reporter.Output.WriteLine(UsageText);
+                return 1;
+            }
+
+            string command = args[0];
+            Func<string[], int> builtIn;
+            args = args.Skip(1).ToArray();
+            if (s_builtIns.TryGetValue(command, out builtIn))
+            {
+                return builtIn(args);
+            }
+            else
+            {
+                CommandResult result = Command.Create(
+                        $"{CommandName}-{command}",
+                        args,
+                        FrameworkConstants.CommonFrameworks.NetStandardApp15)
+                    .Execute();
+                return result.ExitCode;
+            }
+        }
+    }
+}

src/dotnet/commands/dotnet-help/HelpCommand.cs

@@ -36,6 +36,7 @@ Commands:
   migrate       Migrates a project.json based project to a msbuild based project
 
 Advanced Commands:
+  add           Group of commands - run `dotnet add --help` for more information
   nuget         Provides additional NuGet commands
   msbuild       msbuilds a project and all of its dependencies
   vstest        Runs tests from the specified files";