Add DiffBlobs

This lets you diff two arbitrary blobs with arbitrary names.

1 files changed, 47 insertions, 0 deletions

diff --git a/diff_test.go b/diff_test.go
index 464fae6..850ed8e 100644
--- a/diff_test.go
+++ b/diff_test.go
@@ -187,3 +187,50 @@ func createTestTrees(t *testing.T, repo *Repository) (originalTree *Tree, newTre
 
 	return originalTree, newTree
 }
+
+func TestDiffBlobs(t *testing.T) {
+	repo := createTestRepo(t)
+	defer cleanupTestRepo(t, repo)
+
+	odb, err := repo.Odb()
+	checkFatal(t, err)
+
+	id1, err := odb.Write([]byte("hello\nhello\n"), ObjectBlob)
+	checkFatal(t, err)
+
+	id2, err := odb.Write([]byte("hallo\nhallo\n"), ObjectBlob)
+	checkFatal(t, err)
+
+	blob1, err := repo.LookupBlob(id1)
+	checkFatal(t, err)
+
+	blob2, err := repo.LookupBlob(id2)
+	checkFatal(t, err)
+
+	var files, hunks, lines int
+	err = DiffBlobs(blob1, "hi", blob2, "hi", nil,
+		func(delta DiffDelta, progress float64) (DiffForEachHunkCallback, error) {
+			files++
+			return func(hunk DiffHunk) (DiffForEachLineCallback, error) {
+				hunks++
+				return func(line DiffLine) error {
+					lines++
+					return nil
+				}, nil
+			}, nil
+		},
+		DiffDetailLines)
+
+	if files != 1 {
+		t.Fatal("Bad number of files iterated")
+	}
+
+	if hunks != 1 {
+		t.Fatal("Bad number of hunks iterated")
+	}
+
+	// two removals, two additions
+	if lines != 4 {
+		t.Fatalf("Bad number of lines iterated")
+	}
+}