Make Diff.Compare able to handle a blob to blob comparison

2 files changed, 62 insertions, 0 deletions

diff --git a/LibGit2Sharp.Tests/DiffBlobToBlobFixture.cs b/LibGit2Sharp.Tests/DiffBlobToBlobFixture.cs
new file mode 100644
index 00000000..15f36460
--- /dev/null
+++ b/LibGit2Sharp.Tests/DiffBlobToBlobFixture.cs
@@ -0,0 +1,61 @@
+using System.Linq;
+using System.Text;
+using LibGit2Sharp.Tests.TestHelpers;
+using Xunit;
+
+namespace LibGit2Sharp.Tests
+{
+    public class DiffBlobToBlobFixture : BaseFixture
+    {
+        [Fact]
+        public void ComparingABlobAgainstItselfReturnsNoDifference()
+        {
+            using (var repo = new Repository(StandardTestRepoPath))
+            {
+                Blob blob = repo.Head.Tip.Tree.Blobs.First();
+
+                ContentChanges changes = repo.Diff.Compare(blob, blob);
+
+                Assert.Equal(0, changes.LinesAdded);
+                Assert.Equal(0, changes.LinesDeleted);
+                Assert.Equal(string.Empty, changes.Patch);
+            }
+        }
+
+        [Fact]
+        public void CanCompareTwoVersionsOfABlobWithADiffOfTwoHunks()
+        {
+            using (var repo = new Repository(StandardTestRepoPath))
+            {
+                var oldblob = repo.Lookup<Blob>("7909961");
+                var newblob = repo.Lookup<Blob>("4e935b7");
+
+                ContentChanges changes = repo.Diff.Compare(oldblob, newblob);
+
+                Assert.Equal(3, changes.LinesAdded);
+                Assert.Equal(1, changes.LinesDeleted);
+
+                var expected = new StringBuilder()
+                 .Append("@@ -1,4 +1,5 @@\n")
+                 .Append(" 1\n")
+                 .Append("+2\n")
+                 .Append(" 3\n")
+                 .Append(" 4\n")
+                 .Append(" 5\n")
+                 .Append("@@ -8,8 +9,9 @@\n")
+                 .Append(" 8\n")
+                 .Append(" 9\n")
+                 .Append(" 10\n")
+                 .Append("-12\n")
+                 .Append("+11\n")
+                 .Append(" 12\n")
+                 .Append(" 13\n")
+                 .Append(" 14\n")
+                 .Append(" 15\n")
+                 .Append("+16\n");
+
+                Assert.Equal(expected.ToString(), changes.Patch);
+            }
+        }
+    }
+}
diff --git a/LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj b/LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj
index 8187f89e..52b8cbe7 100644
--- a/LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj
+++ b/LibGit2Sharp.Tests/LibGit2Sharp.Tests.csproj
@@ -45,6 +45,7 @@
   <ItemGroup>
     <Compile Include="ConfigurationFixture.cs" />
     <Compile Include="AttributesFixture.cs" />
+    <Compile Include="DiffBlobToBlobFixture.cs" />
     <Compile Include="ObjectDatabaseFixture.cs" />
     <Compile Include="DiffTreeToTreeFixture.cs" />
     <Compile Include="RepositoryOptionsFixture.cs" />