Add CompareOptions

* ContextLines
* InterhunkLines

Closes #423

Author: dahlbyk

LibGit2Sharp.Tests/DiffTreeToTreeFixture.cs

@@ -4,6 +4,7 @@
 using System.Text;
 using LibGit2Sharp.Tests.TestHelpers;
 using Xunit;
+using Xunit.Extensions;
 
 namespace LibGit2Sharp.Tests
 {
@@ -222,23 +223,31 @@ public void CanDetectTheRenamingOfAModifiedFile()
          * $ git diff --shortstat f8d44d7..ec9e401
          *  1 file changed, 2 insertions(+), 1 deletion(-)
          */
-        [Fact]
-        public void CanCompareTwoVersionsOfAFileWithATrailingNewlineDeletion()
+        [Theory]
+        [InlineData(0, 175)]
+        [InlineData(1, 191)]
+        [InlineData(2, 184)]
+        [InlineData(3, 187)]
+        [InlineData(4, 193)]
+        public void CanCompareTwoVersionsOfAFileWithATrailingNewlineDeletion(int contextLines, int expectedPatchLength)
         {
             using (var repo = new Repository(StandardTestRepoPath))
             {
                 Tree rootCommitTree = repo.Lookup<Commit>("f8d44d7").Tree;
                 Tree commitTreeWithUpdatedFile = repo.Lookup<Commit>("ec9e401").Tree;
 
-                TreeChanges changes = repo.Diff.Compare(rootCommitTree, commitTreeWithUpdatedFile);
+                TreeChanges changes = repo.Diff.Compare(rootCommitTree, commitTreeWithUpdatedFile,
+                                                        compareOptions: new CompareOptions { ContextLines = contextLines });
 
                 Assert.Equal(1, changes.Count());
                 Assert.Equal(1, changes.Modified.Count());
+                Assert.Equal(expectedPatchLength, changes.Patch.Length);
 
                 TreeEntryChanges treeEntryChanges = changes.Modified.Single();
 
                 Assert.Equal(2, treeEntryChanges.LinesAdded);
                 Assert.Equal(1, treeEntryChanges.LinesDeleted);
+                Assert.Equal(expectedPatchLength, treeEntryChanges.Patch.Length);
             }
         }
 
@@ -293,15 +302,31 @@ public void CanCompareTwoVersionsOfAFileWithATrailingNewlineDeletion()
          *  super-file.txt                  |    5 +++++
          *  3 files changed, 8 insertions(+), 5 deletions(-)
          */
-        [Fact]
-        public void CanCompareTwoVersionsOfAFileWithADiffOfTwoHunks()
+        [Theory]
+        [InlineData(0, 3)]
+        [InlineData(0, 4)]
+        [InlineData(1, 1)]
+        [InlineData(1, 2)]
+        [InlineData(2, 4)]
+        [InlineData(2, 5)]
+        [InlineData(3, 2)]
+        [InlineData(3, 3)]
+        [InlineData(4, 0)]
+        [InlineData(4, 1)]
+        public void CanCompareTwoVersionsOfAFileWithADiffOfTwoHunks(int contextLines, int interhunkLines)
         {
+            var compareOptions = new CompareOptions
+            {
+                ContextLines = contextLines,
+                InterhunkLines = interhunkLines,
+            };
+
             using (var repo = new Repository(StandardTestRepoPath))
             {
                 Tree rootCommitTree = repo.Lookup<Commit>("f8d44d7").Tree;
                 Tree mergedCommitTree = repo.Lookup<Commit>("7252fe2").Tree;
 
-                TreeChanges changes = repo.Diff.Compare(rootCommitTree, mergedCommitTree);
+                TreeChanges changes = repo.Diff.Compare(rootCommitTree, mergedCommitTree, compareOptions: compareOptions);
 
                 Assert.Equal(3, changes.Count());
                 Assert.Equal(1, changes.Modified.Count());
@@ -314,77 +339,10 @@ public void CanCompareTwoVersionsOfAFileWithADiffOfTwoHunks()
                 Assert.Equal(1, treeEntryChanges.LinesDeleted);
 
                 Assert.Equal(Mode.Nonexistent, changes["my-name-does-not-feel-right.txt"].Mode);
-
-                var expected = new StringBuilder()
-                    .Append("diff --git a/numbers.txt b/numbers.txt\n")
-                    .Append("index 7909961..4e935b7 100644\n")
-                    .Append("--- a/numbers.txt\n")
-                    .Append("+++ b/numbers.txt\n")
-                    .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(), treeEntryChanges.Patch);
-
-                expected = new StringBuilder()
-                    .Append("diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt\n")
-                    .Append("deleted file mode 100644\n")
-                    .Append("index e8953ab..0000000\n")
-                    .Append("--- a/my-name-does-not-feel-right.txt\n")
-                    .Append("+++ /dev/null\n")
-                    .Append("@@ -1,4 +0,0 @@\n")
-                    .Append("-That's a terrible name!\n")
-                    .Append("-I don't like it.\n")
-                    .Append("-People look down at me and laugh. :-(\n")
-                    .Append("-Really!!!!\n")
-                    .Append("diff --git a/numbers.txt b/numbers.txt\n")
-                    .Append("index 7909961..4e935b7 100644\n")
-                    .Append("--- a/numbers.txt\n")
-                    .Append("+++ b/numbers.txt\n")
-                    .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")
-                    .Append("diff --git a/super-file.txt b/super-file.txt\n")
-                    .Append("new file mode 100644\n")
-                    .Append("index 0000000..16bdf1d\n")
-                    .Append("--- /dev/null\n")
-                    .Append("+++ b/super-file.txt\n")
-                    .Append("@@ -0,0 +1,5 @@\n")
-                    .Append("+That's a terrible name!\n")
-                    .Append("+I don't like it.\n")
-                    .Append("+People look down at me and laugh. :-(\n")
-                    .Append("+Really!!!!\n")
-                    .Append("+Yeah! Better!\n");
-
-                Assert.Equal(expected.ToString(), changes.Patch);
+                Assert.Equal(Expected("f8d44d7...7252fe2/numbers.txt-{0}-{1}.diff", contextLines, interhunkLines),
+                             treeEntryChanges.Patch);
+                Assert.Equal(Expected("f8d44d7...7252fe2/full-{0}-{1}.diff", contextLines, interhunkLines),
+                             changes.Patch);
             }
         }
 
@@ -479,7 +437,7 @@ public void ComparingTwoNullTreesReturnsAnEmptyTreeChanges()
         {
             using (var repo = new Repository(StandardTestRepoPath))
             {
-                TreeChanges changes = repo.Diff.Compare(null, null, null);
+                TreeChanges changes = repo.Diff.Compare(default(Tree), default(Tree));
 
                 Assert.Equal(0, changes.Count());
             }

LibGit2Sharp.Tests/MetaFixture.cs

@@ -12,13 +12,14 @@ public class MetaFixture
     {
         private static readonly Type[] excludedTypes = new[]
         {
+            typeof(CompareOptions),
             typeof(Credentials),
+            typeof(ExplicitPathsOptions),
             typeof(Filter),
             typeof(ObjectId),
             typeof(Repository),
             typeof(RepositoryOptions),
             typeof(Signature),
-            typeof(ExplicitPathsOptions),
         };
 
         // Related to https://github.com/libgit2/libgit2sharp/pull/251

LibGit2Sharp.Tests/Resources/expected/f8d44d7...7252fe2/full-0-3.diff

@@ -0,0 +1,32 @@
+diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt
+deleted file mode 100644
+index e8953ab..0000000
+--- a/my-name-does-not-feel-right.txt
++++ /dev/null
+@@ -1,4 +0,0 @@
+-That's a terrible name!
+-I don't like it.
+-People look down at me and laugh. :-(
+-Really!!!!
+diff --git a/numbers.txt b/numbers.txt
+index 7909961..4e935b7 100644
+--- a/numbers.txt
++++ b/numbers.txt
+@@ -1,0 +2 @@
++2
+@@ -11 +12 @@
+-12
++11
+@@ -15,0 +17 @@
++16
+diff --git a/super-file.txt b/super-file.txt
+new file mode 100644
+index 0000000..16bdf1d
+--- /dev/null
++++ b/super-file.txt
+@@ -0,0 +1,5 @@
++That's a terrible name!
++I don't like it.
++People look down at me and laugh. :-(
++Really!!!!
++Yeah! Better!

LibGit2Sharp.Tests/Resources/expected/f8d44d7...7252fe2/full-0-4.diff

@@ -0,0 +1,35 @@
+diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt
+deleted file mode 100644
+index e8953ab..0000000
+--- a/my-name-does-not-feel-right.txt
++++ /dev/null
+@@ -1,4 +0,0 @@
+-That's a terrible name!
+-I don't like it.
+-People look down at me and laugh. :-(
+-Really!!!!
+diff --git a/numbers.txt b/numbers.txt
+index 7909961..4e935b7 100644
+--- a/numbers.txt
++++ b/numbers.txt
+@@ -1,0 +2 @@
++2
+@@ -11,5 +12,6 @@
+-12
++11
+ 12
+ 13
+ 14
+ 15
++16
+diff --git a/super-file.txt b/super-file.txt
+new file mode 100644
+index 0000000..16bdf1d
+--- /dev/null
++++ b/super-file.txt
+@@ -0,0 +1,5 @@
++That's a terrible name!
++I don't like it.
++People look down at me and laugh. :-(
++Really!!!!
++Yeah! Better!

LibGit2Sharp.Tests/Resources/expected/f8d44d7...7252fe2/full-1-1.diff

@@ -0,0 +1,37 @@
+diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt
+deleted file mode 100644
+index e8953ab..0000000
+--- a/my-name-does-not-feel-right.txt
++++ /dev/null
+@@ -1,4 +0,0 @@
+-That's a terrible name!
+-I don't like it.
+-People look down at me and laugh. :-(
+-Really!!!!
+diff --git a/numbers.txt b/numbers.txt
+index 7909961..4e935b7 100644
+--- a/numbers.txt
++++ b/numbers.txt
+@@ -1,2 +1,3 @@
+ 1
++2
+ 3
+@@ -10,3 +11,3 @@
+ 10
+-12
++11
+ 12
+@@ -15 +16,2 @@
+ 15
++16
+diff --git a/super-file.txt b/super-file.txt
+new file mode 100644
+index 0000000..16bdf1d
+--- /dev/null
++++ b/super-file.txt
+@@ -0,0 +1,5 @@
++That's a terrible name!
++I don't like it.
++People look down at me and laugh. :-(
++Really!!!!
++Yeah! Better!

LibGit2Sharp.Tests/Resources/expected/f8d44d7...7252fe2/full-1-2.diff

@@ -0,0 +1,38 @@
+diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt
+deleted file mode 100644
+index e8953ab..0000000
+--- a/my-name-does-not-feel-right.txt
++++ /dev/null
+@@ -1,4 +0,0 @@
+-That's a terrible name!
+-I don't like it.
+-People look down at me and laugh. :-(
+-Really!!!!
+diff --git a/numbers.txt b/numbers.txt
+index 7909961..4e935b7 100644
+--- a/numbers.txt
++++ b/numbers.txt
+@@ -1,2 +1,3 @@
+ 1
++2
+ 3
+@@ -10,6 +11,7 @@
+ 10
+-12
++11
+ 12
+ 13
+ 14
+ 15
++16
+diff --git a/super-file.txt b/super-file.txt
+new file mode 100644
+index 0000000..16bdf1d
+--- /dev/null
++++ b/super-file.txt
+@@ -0,0 +1,5 @@
++That's a terrible name!
++I don't like it.
++People look down at me and laugh. :-(
++Really!!!!
++Yeah! Better!

LibGit2Sharp.Tests/Resources/expected/f8d44d7...7252fe2/full-2-4.diff

@@ -0,0 +1,40 @@
+diff --git a/my-name-does-not-feel-right.txt b/my-name-does-not-feel-right.txt
+deleted file mode 100644
+index e8953ab..0000000
+--- a/my-name-does-not-feel-right.txt
++++ /dev/null
+@@ -1,4 +0,0 @@
+-That's a terrible name!
+-I don't like it.
+-People look down at me and laugh. :-(
+-Really!!!!
+diff --git a/numbers.txt b/numbers.txt
+index 7909961..4e935b7 100644
+--- a/numbers.txt
++++ b/numbers.txt
+@@ -1,3 +1,4 @@
+ 1
++2
+ 3
+ 4
+@@ -9,7 +10,8 @@
+ 9
+ 10
+-12
++11
+ 12
+ 13
+ 14
+ 15
++16
+diff --git a/super-file.txt b/super-file.txt
+new file mode 100644
+index 0000000..16bdf1d
+--- /dev/null
++++ b/super-file.txt
+@@ -0,0 +1,5 @@
++That's a terrible name!
++I don't like it.
++People look down at me and laugh. :-(
++Really!!!!
++Yeah! Better!