Make Diff mockable

Author: yorah

LibGit2Sharp/Diff.cs

@@ -50,6 +50,12 @@ private static FilePath[] ToFilePaths(IEnumerable<string> paths)
             return filePaths.ToArray();
         }
 
+        /// <summary>
+        ///   Needed for mocking purposes.
+        /// </summary>
+        protected Diff()
+        { }
+
         internal Diff(Repository repo)
         {
             this.repo = repo;
@@ -62,7 +68,7 @@ internal Diff(Repository repo)
         /// <param name = "newTree">The <see cref = "Tree"/> you want to compare to.</param>
         /// <param name = "paths">The list of paths (either files or directories) that should be compared.</param>
         /// <returns>A <see cref = "TreeChanges"/> containing the changes between the <paramref name = "oldTree"/> and the <paramref name = "newTree"/>.</returns>
-        public TreeChanges Compare(Tree oldTree, Tree newTree, IEnumerable<string> paths = null)
+        public virtual TreeChanges Compare(Tree oldTree, Tree newTree, IEnumerable<string> paths = null)
         {
             using(GitDiffOptions options = BuildOptions(paths))
             using (DiffListSafeHandle diff = BuildDiffListFromTrees(oldTree.Id, newTree.Id, options))
@@ -89,7 +95,7 @@ private DiffListSafeHandle BuildDiffListFromTrees(ObjectId oldTree, ObjectId new
         /// <param name = "oldBlob">The <see cref = "Blob"/> you want to compare from.</param>
         /// <param name = "newBlob">The <see cref = "Blob"/> you want to compare to.</param>
         /// <returns>A <see cref = "ContentChanges"/> containing the changes between the <paramref name = "oldBlob"/> and the <paramref name = "newBlob"/>.</returns>
-        public ContentChanges Compare(Blob oldBlob, Blob newBlob)
+        public virtual ContentChanges Compare(Blob oldBlob, Blob newBlob)
         {
             using (GitDiffOptions options = BuildOptions())
             {
@@ -114,7 +120,7 @@ private static IDictionary<DiffTarget, Func<Repository, TreeComparisonHandleRetr
         /// <param name = "diffTarget">The target to compare to.</param>
         /// <param name = "paths">The list of paths (either files or directories) that should be compared.</param>
         /// <returns>A <see cref = "TreeChanges"/> containing the changes between the <see cref="Tree"/> and the selected target.</returns>
-        public TreeChanges Compare(Tree oldTree, DiffTarget diffTarget, IEnumerable<string> paths = null)
+        public virtual TreeChanges Compare(Tree oldTree, DiffTarget diffTarget, IEnumerable<string> paths = null)
         {
             var comparer = handleRetrieverDispatcher[diffTarget](repo);