Make dotnet project convert interactive

src/Cli/dotnet/Commands/CliCommandStrings.resx

@@ -1501,6 +1501,37 @@ Tool '{1}' (version '{2}') was successfully installed. Entry is added to the man
   <data name="ProjectConvertAppFullName" xml:space="preserve">
     <value>Convert a file-based program to a project-based program.</value>
   </data>
+  <data name="ProjectConvertAskForOutputDirectory" xml:space="preserve">
+    <value>Specify the output directory ({0}):</value>
+    <comment>{0} is the default value</comment>
+  </data>
+  <data name="ProjectConvertDryRun" xml:space="preserve">
+    <value>Determines changes without actually modifying the file system</value>
+  </data>
+  <data name="ProjectConvertWouldCreateDirectory" xml:space="preserve">
+    <value>Dry run: would create directory: {0}</value>
+    <comment>{0} is the directory full path.</comment>
+  </data>
+  <data name="ProjectConvertWouldCopyFile" xml:space="preserve">
+    <value>Dry run: would copy file '{0}' to '{1}'.</value>
+    <comment>{0} and {1} are file full paths.</comment>
+  </data>
+  <data name="ProjectConvertWouldConvertFile" xml:space="preserve">
+    <value>Dry run: would remove file-level directives from file: {0}</value>
+    <comment>{0} is the file full path.</comment>
+  </data>
+  <data name="ProjectConvertWouldMoveFile" xml:space="preserve">
+    <value>Dry run: would move file '{0}' to '{1}'.</value>
+    <comment>{0} and {1} are file full paths.</comment>
+  </data>
+  <data name="ProjectConvertWouldDeleteFile" xml:space="preserve">
+    <value>Dry run: would delete file: {0}</value>
+    <comment>{0} is the file full path.</comment>
+  </data>
+  <data name="ProjectConvertWouldCreateFile" xml:space="preserve">
+    <value>Dry run: would create file: {0}</value>
+    <comment>{0} is the file full path.</comment>
+  </data>
   <data name="ProjectManifest" xml:space="preserve">
     <value>PROJECT_MANIFEST</value>
   </data>

src/Cli/dotnet/Commands/Project/Convert/ProjectConvertCommand.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.CommandLine;
+using System.Diagnostics.CodeAnalysis;
 using Microsoft.Build.Evaluation;
 using Microsoft.DotNet.Cli.Commands.Run;
 using Microsoft.DotNet.Cli.Utils;
@@ -17,17 +18,14 @@ internal sealed class ProjectConvertCommand(ParseResult parseResult) : CommandBa
 
     public override int Execute()
     {
+        // Check the entry point file path.
         string file = Path.GetFullPath(_file);
         if (!VirtualProjectBuildingCommand.IsValidEntryPointPath(file))
         {
             throw new GracefulException(CliCommandStrings.InvalidFilePath, file);
         }
 
-        string targetDirectory = _outputDirectory ?? Path.ChangeExtension(file, null);
-        if (Directory.Exists(targetDirectory))
-        {
-            throw new GracefulException(CliCommandStrings.DirectoryAlreadyExists, targetDirectory);
-        }
+        string targetDirectory = DetermineOutputDirectory(file);
 
         // Find directives (this can fail, so do this before creating the target directory).
         var sourceFile = VirtualProjectBuildingCommand.LoadSourceFile(file);
@@ -36,28 +34,37 @@ public override int Execute()
         // Find other items to copy over, e.g., default Content items like JSON files in Web apps.
         var includeItems = FindIncludedItems().ToList();
 
-        Directory.CreateDirectory(targetDirectory);
+        bool dryRun = _parseResult.GetValue(ProjectConvertCommandParser.DryRunOption);
+
+        CreateDirectory(targetDirectory);
 
         var targetFile = Path.Join(targetDirectory, Path.GetFileName(file));
 
-        // If there were any directives, remove them from the file.
-        if (directives.Length != 0)
+        // Process the entry point file.
+        if (dryRun)
         {
-            VirtualProjectBuildingCommand.RemoveDirectivesFromFile(directives, sourceFile.Text, targetFile);
-            File.Delete(file);
+            Reporter.Output.WriteLine(CliCommandStrings.ProjectConvertWouldCopyFile, file, targetFile);
+            Reporter.Output.WriteLine(CliCommandStrings.ProjectConvertWouldConvertFile, targetFile);
         }
         else
         {
-            File.Move(file, targetFile);
+            VirtualProjectBuildingCommand.RemoveDirectivesFromFile(directives, sourceFile.Text, targetFile);
         }
 
         // Create project file.
         string projectFile = Path.Join(targetDirectory, Path.GetFileNameWithoutExtension(file) + ".csproj");
-        using var stream = File.Open(projectFile, FileMode.Create, FileAccess.Write);
-        using var writer = new StreamWriter(stream, Encoding.UTF8);
-        VirtualProjectBuildingCommand.WriteProjectFile(writer, directives, isVirtualProject: false);
+        if (dryRun)
+        {
+            Reporter.Output.WriteLine(CliCommandStrings.ProjectConvertWouldCreateFile, projectFile);
+        }
+        else
+        {
+            using var stream = File.Open(projectFile, FileMode.Create, FileAccess.Write);
+            using var writer = new StreamWriter(stream, Encoding.UTF8);
+            VirtualProjectBuildingCommand.WriteProjectFile(writer, directives, isVirtualProject: false);
+        }
 
-        // Copy over included items.
+        // Copy or move over included items.
         foreach (var item in includeItems)
         {
             string targetItemFullPath = Path.Combine(targetDirectory, item.RelativePath);
@@ -69,12 +76,39 @@ public override int Execute()
             }
 
             string targetItemDirectory = Path.GetDirectoryName(targetItemFullPath)!;
-            Directory.CreateDirectory(targetItemDirectory);
-            File.Copy(item.FullPath, targetItemFullPath);
+            CreateDirectory(targetItemDirectory);
+            CopyFile(item.FullPath, targetItemFullPath);
         }
 
         return 0;
 
+        void CreateDirectory(string path)
+        {
+            if (dryRun)
+            {
+                if (!Directory.Exists(path))
+                {
+                    Reporter.Output.WriteLine(CliCommandStrings.ProjectConvertWouldCreateDirectory, path);
+                }
+            }
+            else
+            {
+                Directory.CreateDirectory(path);
+            }
+        }
+
+        void CopyFile(string source, string target)
+        {
+            if (dryRun)
+            {
+                Reporter.Output.WriteLine(CliCommandStrings.ProjectConvertWouldCopyFile, source, target);
+            }
+            else
+            {
+                File.Copy(source, target);
+            }
+        }
+
         IEnumerable<(string FullPath, string RelativePath)> FindIncludedItems()
         {
             string entryPointFileDirectory = PathUtility.EnsureTrailingSlash(Path.GetDirectoryName(file)!);
@@ -118,4 +152,42 @@ public override int Execute()
             }
         }
     }
+
+    private string DetermineOutputDirectory(string file)
+    {
+        string defaultValue = Path.ChangeExtension(file, null);
+        string defaultValueRelative = Path.GetRelativePath(relativeTo: Environment.CurrentDirectory, defaultValue);
+        string targetDirectory = _outputDirectory
+            ?? TryAskForOutputDirectory(defaultValueRelative)
+            ?? defaultValue;
+        if (Directory.Exists(targetDirectory))
+        {
+            throw new GracefulException(CliCommandStrings.DirectoryAlreadyExists, targetDirectory);
+        }
+
+        return targetDirectory;
+    }
+
+    private string? TryAskForOutputDirectory(string defaultValueRelative)
+    {
+        return InteractiveConsole.Ask<string?>(
+            string.Format(CliCommandStrings.ProjectConvertAskForOutputDirectory, defaultValueRelative),
+            _parseResult,
+            (path, out result, [NotNullWhen(returnValue: false)] out error) =>
+            {
+                if (Directory.Exists(path))
+                {
+                    result = null;
+                    error = string.Format(CliCommandStrings.DirectoryAlreadyExists, Path.GetFullPath(path));
+                    return false;
+                }
+
+                result = path is null ? null : Path.GetFullPath(path);
+                error = null;
+                return true;
+            },
+            out var result)
+            ? result
+            : null;
+    }
 }

src/Cli/dotnet/Commands/Project/Convert/ProjectConvertCommandParser.cs

@@ -20,13 +20,21 @@ internal sealed class ProjectConvertCommandParser
         Arity = ArgumentArity.Zero,
     };
 
+    public static readonly Option<bool> DryRunOption = new("--dry-run")
+    {
+        Description = CliCommandStrings.ProjectConvertDryRun,
+        Arity = ArgumentArity.Zero,
+    };
+
     public static Command GetCommand()
     {
         Command command = new("convert", CliCommandStrings.ProjectConvertAppFullName)
         {
             FileArgument,
             SharedOptions.OutputOption,
             ForceOption,
+            CommonOptions.InteractiveOption(),
+            DryRunOption,
         };
 
         command.SetAction((parseResult) => new ProjectConvertCommand(parseResult).Execute());

src/Cli/dotnet/Commands/Tool/Execute/ToolExecuteCommand.cs

@@ -30,7 +30,6 @@ internal class ToolExecuteCommand(ParseResult result, ToolManifestFinder? toolMa
     private readonly string[] _addSource = result.GetValue(ToolExecuteCommandParser.AddSourceOption) ?? [];
     private readonly bool _interactive = result.GetValue(ToolExecuteCommandParser.InteractiveOption);
     private readonly VerbosityOptions _verbosity = result.GetValue(ToolExecuteCommandParser.VerbosityOption);
-    private readonly bool _yes = result.GetValue(ToolExecuteCommandParser.YesOption);
     private readonly IToolPackageDownloader _toolPackageDownloader = ToolPackageFactory.CreateToolPackageStoresAndDownloader().downloader;
 
     private readonly RestoreActionConfig _restoreActionConfig = new RestoreActionConfig(DisableParallel: result.GetValue(ToolCommandRestorePassThroughOptions.DisableParallelOption),
@@ -128,47 +127,7 @@ public override int Execute()
 
     private bool UserAgreedToRunFromSource(PackageId packageId, NuGetVersion version, PackageSource source)
     {
-        if (_yes)
-        {
-            return true;
-        }
-
-        if (!_interactive)
-        {
-            return false;
-        }
-
         string promptMessage = string.Format(CliCommandStrings.ToolDownloadConfirmationPrompt, packageId, version.ToString(), source.Source);
-
-        static string AddPromptOptions(string message)
-        {
-            return $"{message} [{CliCommandStrings.ConfirmationPromptYesValue}/{CliCommandStrings.ConfirmationPromptNoValue}] ({CliCommandStrings.ConfirmationPromptYesValue}): ";
-        }
-
-        Console.Write(AddPromptOptions(promptMessage));
-
-        static bool KeyMatches(ConsoleKeyInfo pressedKey, string valueKey)
-        {
-            //  Apparently you can't do invariant case insensitive comparison on a char directly, so we have to convert it to a string.
-            //  The resource string should be a single character, but we take the first character just to be sure.
-            return pressedKey.KeyChar.ToString().ToLowerInvariant().Equals(
-                    valueKey.ToLowerInvariant().Substring(0, 1));
-        }
-
-        while (true)
-        {
-            var key = Console.ReadKey();
-            Console.WriteLine();
-            if (key.Key == ConsoleKey.Enter || KeyMatches(key, CliCommandStrings.ConfirmationPromptYesValue))
-            {
-                return true;
-            }
-            if (key.Key == ConsoleKey.Escape || KeyMatches(key, CliCommandStrings.ConfirmationPromptNoValue))
-            {
-                return false;
-            }
-
-            Console.Write(AddPromptOptions(string.Format(CliCommandStrings.ConfirmationPromptInvalidChoiceMessage, CliCommandStrings.ConfirmationPromptYesValue, CliCommandStrings.ConfirmationPromptNoValue)));
-        }
+        return InteractiveConsole.Confirm(promptMessage, _parseResult, acceptEscapeForFalse: true) == true;
     }
 }