Adding base add package sub command

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

@@ -4,6 +4,7 @@
 using System;
 using System.Collections.Generic;
 using Microsoft.DotNet.Cli;
+using Microsoft.DotNet.Tools.Add.PackageReference;
 using Microsoft.DotNet.Tools.Add.ProjectToProjectReference;
 using Microsoft.DotNet.Tools.Add.ProjectToSolution;
 
@@ -18,6 +19,7 @@ namespace Microsoft.DotNet.Tools.Add
             {
                 AddProjectToSolutionCommand.Create,
                 AddProjectToProjectReferenceCommand.Create,
+                AddPackageReferenceCommand.Create
             };
 
         public static int Run(string[] args)
@@ -26,4 +28,4 @@ namespace Microsoft.DotNet.Tools.Add
             return command.RunCommand(args);
         }
     }
-}
+}

src/dotnet/commands/dotnet-add/dotnet-add-package/LocalizableStrings.cs

@@ -0,0 +1,22 @@
+// 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.
+
+namespace Microsoft.DotNet.Tools.Add.PackageReference
+{
+    internal class LocalizableStrings
+    {
+        public const string AppFullName = ".NET Add Package reference Command";
+
+        public const string AppDescription = "Command to add package reference";
+
+        public const string AppHelpText = "Package references to add";
+
+        public const string CmdFrameworkDescription = "Add reference only when targetting a specific framework";
+
+        public const string CmdNoRestoreDescription = "Add reference without performing restore preview and compatibility check.";
+
+        public const string CmdSourceDescription = "Use specific NuGet package sources to use during the restore.";
+
+        public const string CmdPackageDirectoryDescription = "Restore the packages to this Directory .";
+    }
+}

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

@@ -0,0 +1,130 @@
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Text;
+using Microsoft.Build.Evaluation;
+using Microsoft.DotNet.Cli;
+using Microsoft.DotNet.Cli.CommandLine;
+using Microsoft.DotNet.Cli.Utils;
+using Microsoft.DotNet.Tools.Common;
+using Microsoft.DotNet.Tools.MSBuild;
+using NuGet.Frameworks;
+
+namespace Microsoft.DotNet.Tools.Add.PackageReference
+{
+    internal class AddPackageReferenceCommand : DotNetSubCommandBase
+    {
+        private CommandOption _frameworkOption;
+        private CommandOption _noRestore;
+        private CommandOption _source;
+        private CommandOption _packageDirectory;
+
+        public static DotNetSubCommandBase Create()
+        {
+            var command = new AddPackageReferenceCommand()
+            {
+                Name = "package",
+                FullName = LocalizableStrings.AppFullName,
+                Description = LocalizableStrings.AppDescription,
+                HandleRemainingArguments = true,
+                ArgumentSeparatorHelpText = LocalizableStrings.AppHelpText,
+            };
+
+            command.HelpOption("-h|--help");
+
+            command._frameworkOption = command.Option(
+               $"-f|--framework",
+               LocalizableStrings.CmdFrameworkDescription,
+               CommandOptionType.SingleValue);
+
+            command._noRestore = command.Option(
+                $"-n|--no-restore ",
+               LocalizableStrings.CmdNoRestoreDescription,
+               CommandOptionType.NoValue);
+
+            command._source = command.Option(
+                $"-s|--source ",
+                LocalizableStrings.CmdSourceDescription,
+                CommandOptionType.SingleValue);
+
+            command._packageDirectory = command.Option(
+                $"--package-directory",
+                LocalizableStrings.CmdPackageDirectoryDescription,
+                CommandOptionType.SingleValue);
+
+            return command;
+        }
+
+        public override int Run(string fileOrDirectory)
+        {
+            WaitForDebugger();
+            var projects = new ProjectCollection();
+            var msbuildProj = MsbuildProject.FromFileOrDirectory(projects, fileOrDirectory);
+
+            if (RemainingArguments.Count == 0)
+            {
+                throw new GracefulException(CommonLocalizableStrings.SpecifyAtLeastOneReferenceToAdd);
+            }
+
+            var tempDgFilePath = CreateTemporaryFile(".dg");
+
+            GetProjectDependencyGraph(msbuildProj.ProjectDirectory, tempDgFilePath);
+
+            DisposeTemporaryFile(tempDgFilePath);
+
+            return 0;
+        }
+
+        private void GetProjectDependencyGraph(string projectFilePath,
+            string dgFilePath)
+        {
+            var args = new List<string>();
+
+            // Pass the task as generate restore dg file
+            args.Add("/t:GenerateRestoreGraphFile");
+
+            // Pass dg file output path
+            args.Add(string.Format("/p:RestoreGraphOutputPath={0}{1}{2}", '"', dgFilePath, '"'));
+
+            var result = new MSBuildForwardingApp(args).Execute();
+
+            if (result != 0)
+            {
+                throw new GracefulException("Could not generate dg file");
+            }
+        }
+
+        private string CreateTemporaryFile(string extension)
+        {
+            var tempDirectory = Path.GetTempPath();
+            var tempFile = Path.Combine(tempDirectory, Guid.NewGuid().ToString() + extension);
+            File.Create(tempFile).Dispose();
+            return tempFile;
+        }
+
+        private void DisposeTemporaryFile(string filePath)
+        {
+            if (File.Exists(filePath))
+            {
+                File.Delete(filePath);
+            }
+        }
+
+        public void WaitForDebugger()
+        {
+            Console.WriteLine("Waiting for debugger to attach.");
+            Console.WriteLine($"Process ID: {Process.GetCurrentProcess().Id}");
+
+            while (!Debugger.IsAttached)
+            {
+                System.Threading.Thread.Sleep(100);
+            }
+            Debugger.Break();
+        }
+    }
+}