2 files changed, 43 insertions, 0 deletions
diff --git a/storage/filesystem/internal/dotgit/dotgit.go b/storage/filesystem/internal/dotgit/dotgit.go
index f9763d1..1281b7e 100644
--- a/storage/filesystem/internal/dotgit/dotgit.go
+++ b/storage/filesystem/internal/dotgit/dotgit.go
@@ -18,6 +18,7 @@ const (
 	suffix         = ".git"
 	packedRefsPath = "packed-refs"
 	configPath     = "config"
+	indexPath      = "index"
 	shallowPath    = "shallow"
 
 	objectsPath = "objects"
@@ -72,6 +73,16 @@ func (d *DotGit) Config() (billy.File, error) {
 	return d.fs.Open(configPath)
 }
 
+// IndexWriter returns a file pointer for write to the index file
+func (d *DotGit) IndexWriter() (billy.File, error) {
+	return d.fs.Create(indexPath)
+}
+
+// Index returns a file pointer for read to the index file
+func (d *DotGit) Index() (billy.File, error) {
+	return d.fs.Open(indexPath)
+}
+
 // ShallowWriter returns a file pointer for write to the shallow file
 func (d *DotGit) ShallowWriter() (billy.File, error) {
 	return d.fs.Create(shallowPath)
diff --git a/storage/filesystem/internal/dotgit/dotgit_test.go b/storage/filesystem/internal/dotgit/dotgit_test.go
index 48f02f0..bff90af 100644
--- a/storage/filesystem/internal/dotgit/dotgit_test.go
+++ b/storage/filesystem/internal/dotgit/dotgit_test.go
@@ -154,6 +154,38 @@ func (s *SuiteDotGit) TestConfigWriteAndConfig(c *C) {
 	c.Assert(string(cnt), Equals, "foo")
 }
 
+func (s *SuiteDotGit) TestIndex(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	idx, err := dir.Index()
+	c.Assert(err, IsNil)
+	c.Assert(idx, NotNil)
+}
+
+func (s *SuiteDotGit) TestIndexWriteAndIndex(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+
+	f, err := dir.IndexWriter()
+	c.Assert(err, IsNil)
+
+	_, err = f.Write([]byte("foo"))
+	c.Assert(err, IsNil)
+
+	f, err = dir.Index()
+	c.Assert(err, IsNil)
+
+	cnt, err := ioutil.ReadAll(f)
+	c.Assert(err, IsNil)
+
+	c.Assert(string(cnt), Equals, "foo")
+}
+
 func (s *SuiteDotGit) TestShallow(c *C) {
 	fs := fixtures.Basic().ByTag(".git").One().DotGit()
 	dir := New(fs)