feedback (added extension method to format string with double quotes)

src/NuGet.Core/NuGet.Common/Migrations/Migration1.cs

@@ -156,13 +156,13 @@ private static void FixPermissions(string path, PosixPermissions umask)
             {
                 PosixPermissions correctedPermissions = permissions.Value.WithUmask(umask);
                 string correctedPermissionsString = correctedPermissions.ToString();
-                Exec("chmod", correctedPermissionsString + " " + "\"" + path + "\"");
+                Exec("chmod", correctedPermissionsString + " " + path.FormatWithDoubleQuotes());
             }
         }
 
         internal static PosixPermissions? GetPermissions(string path)
         {
-            string output = Exec("ls", "-ld " + "\"" + path + "\"");
+            string output = Exec("ls", "-ld " + path.FormatWithDoubleQuotes());
             if (output == null)
             {
                 return null;

src/NuGet.Core/NuGet.Common/StringExtensions.cs

@@ -0,0 +1,13 @@
+// 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.
+
+namespace NuGet.Common
+{
+    internal static class StringExtensions
+    {
+        internal static string FormatWithDoubleQuotes(this string s)
+        {
+            return s == null ? s : $@"""{s}""";
+        }
+    }
+}

test/NuGet.Core.Tests/NuGet.Common.Test/StringExtensionsTests.cs

@@ -0,0 +1,35 @@
+// 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 System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace NuGet.Common.Test
+{
+    public class StringExtensionsTests
+    {
+        [Fact]
+        public void FormatWithDoubleQuotes_WhenNullIsPassedReturnsNull_Success()
+        {
+            string actual = null;
+            string formatted = actual.FormatWithDoubleQuotes();
+            Assert.Equal(actual, formatted);
+        }
+
+        [Theory]
+        [InlineData("")]
+        [InlineData("/home/user/NuGet AppData/share")]
+        [InlineData("/home/user/NuGet/share")]
+        [InlineData(@"c:\users\NuGet App\Share")]
+        [InlineData(@"c:\users\NuGet\Share")]
+        public void FormatWithDoubleQuotes_WhenNonNullStringIsPassedReturnsFormattedString_Success(string actual)
+        {
+            string formatted = actual.FormatWithDoubleQuotes();
+            Assert.Equal($@"""{actual}""", formatted);
+        }
+    }
+}