Add some `DebuggerDisplay` love

I followed implementation best practices as described at http://blogs.msdn.com/b/jaredpar/archive/2011/03/18/debuggerdisplay-attribute-best-practices.aspx
Also added a Meta test to make sure the same implementation is used everywhere when using `[DebuggerDisplay]`.

1 files changed, 7 insertions, 0 deletions

diff --git a/LibGit2Sharp/Index.cs b/LibGit2Sharp/Index.cs
index 9cdbbd95..8a9f8d4d 100644
--- a/LibGit2Sharp/Index.cs
+++ b/LibGit2Sharp/Index.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Globalization;
 using System.IO;
 using System.Runtime.InteropServices;
@@ -14,6 +15,7 @@ namespace LibGit2Sharp
     ///   The Index is a staging area between the Working directory and the Repository.
     ///   It's used to prepare and aggregate the changes that will be part of the next commit.
     /// </summary>
+    [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public class Index : IEnumerable<IndexEntry>
     {
         private readonly IndexSafeHandle handle;
@@ -499,5 +501,10 @@ namespace LibGit2Sharp
             Proxy.git_index_add(handle, indexEntry);
             Marshal.FreeHGlobal(indexEntry.Path);
         }
+
+        private string DebuggerDisplay
+        {
+            get { return string.Format("Count = {0}", Count); }
+        }
     }
 }