dotgit: Move package outside internal.

Signed-off-by: Antonio Jesus Navarro Perez <antnavper@gmail.com>

1 files changed, 683 insertions, 0 deletions

diff --git a/storage/filesystem/dotgit/dotgit_test.go b/storage/filesystem/dotgit/dotgit_test.go
new file mode 100644
index 0000000..7733eef
--- /dev/null
+++ b/storage/filesystem/dotgit/dotgit_test.go
@@ -0,0 +1,683 @@
+package dotgit
+
+import (
+	"bufio"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-billy.v4/osfs"
+	"gopkg.in/src-d/go-git-fixtures.v3"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type SuiteDotGit struct {
+	fixtures.Suite
+}
+
+var _ = Suite(&SuiteDotGit{})
+
+func (s *SuiteDotGit) TestInitialize(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+
+	err = dir.Initialize()
+	c.Assert(err, IsNil)
+
+	_, err = fs.Stat(fs.Join("objects", "info"))
+	c.Assert(err, IsNil)
+
+	_, err = fs.Stat(fs.Join("objects", "pack"))
+	c.Assert(err, IsNil)
+
+	_, err = fs.Stat(fs.Join("refs", "heads"))
+	c.Assert(err, IsNil)
+
+	_, err = fs.Stat(fs.Join("refs", "tags"))
+	c.Assert(err, IsNil)
+}
+
+func (s *SuiteDotGit) TestSetRefs(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+
+	firstFoo := plumbing.NewReferenceFromStrings(
+		"refs/heads/foo",
+		"e8d3ffab552895c19b9fcf7aa264d277cde33881",
+	)
+	err = dir.SetRef(firstFoo, nil)
+
+	c.Assert(err, IsNil)
+
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/symbolic",
+		"ref: refs/heads/foo",
+	), nil)
+
+	c.Assert(err, IsNil)
+
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"bar",
+		"e8d3ffab552895c19b9fcf7aa264d277cde33881",
+	), nil)
+	c.Assert(err, IsNil)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+	c.Assert(refs, HasLen, 2)
+
+	ref := findReference(refs, "refs/heads/foo")
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
+
+	ref = findReference(refs, "refs/heads/symbolic")
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Target().String(), Equals, "refs/heads/foo")
+
+	ref = findReference(refs, "bar")
+	c.Assert(ref, IsNil)
+
+	ref, err = dir.Ref("refs/heads/foo")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
+
+	ref, err = dir.Ref("refs/heads/symbolic")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Target().String(), Equals, "refs/heads/foo")
+
+	ref, err = dir.Ref("bar")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
+
+	// Check that SetRef with a non-nil `old` works.
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/foo",
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+	), firstFoo)
+	c.Assert(err, IsNil)
+
+	// `firstFoo` is no longer the right `old` reference, so this
+	// should fail.
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/foo",
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5",
+	), firstFoo)
+	c.Assert(err, NotNil)
+}
+
+func (s *SuiteDotGit) TestRefsFromPackedRefs(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+
+	ref := findReference(refs, "refs/remotes/origin/branch")
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
+
+}
+
+func (s *SuiteDotGit) TestRefsFromReferenceFile(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+
+	ref := findReference(refs, "refs/remotes/origin/HEAD")
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Type(), Equals, plumbing.SymbolicReference)
+	c.Assert(string(ref.Target()), Equals, "refs/remotes/origin/master")
+
+}
+
+func BenchmarkRefMultipleTimes(b *testing.B) {
+	fixtures.Init()
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	refname := plumbing.ReferenceName("refs/remotes/origin/branch")
+
+	dir := New(fs)
+	_, err := dir.Ref(refname)
+	if err != nil {
+		b.Fatalf("unexpected error: %s", err)
+	}
+
+	for i := 0; i < b.N; i++ {
+		_, err := dir.Ref(refname)
+		if err != nil {
+			b.Fatalf("unexpected error: %s", err)
+		}
+	}
+}
+
+func (s *SuiteDotGit) TestRemoveRefFromReferenceFile(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	name := plumbing.ReferenceName("refs/remotes/origin/HEAD")
+	err := dir.RemoveRef(name)
+	c.Assert(err, IsNil)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+
+	ref := findReference(refs, string(name))
+	c.Assert(ref, IsNil)
+}
+
+func (s *SuiteDotGit) TestRemoveRefFromPackedRefs(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	name := plumbing.ReferenceName("refs/remotes/origin/master")
+	err := dir.RemoveRef(name)
+	c.Assert(err, IsNil)
+
+	b, err := ioutil.ReadFile(filepath.Join(fs.Root(), packedRefsPath))
+	c.Assert(err, IsNil)
+
+	c.Assert(string(b), Equals, ""+
+		"# pack-refs with: peeled fully-peeled \n"+
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5 refs/heads/master\n"+
+		"e8d3ffab552895c19b9fcf7aa264d277cde33881 refs/remotes/origin/branch\n")
+}
+
+func (s *SuiteDotGit) TestRemoveRefFromReferenceFileAndPackedRefs(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	// Make a ref file for a ref that's already in `packed-refs`.
+	err := dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/remotes/origin/branch",
+		"e8d3ffab552895c19b9fcf7aa264d277cde33881",
+	), nil)
+
+	// Make sure it only appears once in the refs list.
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+	found := false
+	for _, ref := range refs {
+		if ref.Name() == "refs/remotes/origin/branch" {
+			c.Assert(found, Equals, false)
+			found = true
+		}
+	}
+
+	name := plumbing.ReferenceName("refs/remotes/origin/branch")
+	err = dir.RemoveRef(name)
+	c.Assert(err, IsNil)
+
+	b, err := ioutil.ReadFile(filepath.Join(fs.Root(), packedRefsPath))
+	c.Assert(err, IsNil)
+
+	c.Assert(string(b), Equals, ""+
+		"# pack-refs with: peeled fully-peeled \n"+
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5 refs/heads/master\n"+
+		"6ecf0ef2c2dffb796033e5a02219af86ec6584e5 refs/remotes/origin/master\n")
+
+	refs, err = dir.Refs()
+	c.Assert(err, IsNil)
+
+	ref := findReference(refs, string(name))
+	c.Assert(ref, IsNil)
+}
+
+func (s *SuiteDotGit) TestRemoveRefNonExistent(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	packedRefs := filepath.Join(fs.Root(), packedRefsPath)
+	before, err := ioutil.ReadFile(packedRefs)
+	c.Assert(err, IsNil)
+
+	name := plumbing.ReferenceName("refs/heads/nonexistent")
+	err = dir.RemoveRef(name)
+	c.Assert(err, IsNil)
+
+	after, err := ioutil.ReadFile(packedRefs)
+	c.Assert(err, IsNil)
+
+	c.Assert(string(before), Equals, string(after))
+}
+
+func (s *SuiteDotGit) TestRemoveRefInvalidPackedRefs(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	packedRefs := filepath.Join(fs.Root(), packedRefsPath)
+	brokenContent := "BROKEN STUFF REALLY BROKEN"
+
+	err := ioutil.WriteFile(packedRefs, []byte(brokenContent), os.FileMode(0755))
+	c.Assert(err, IsNil)
+
+	name := plumbing.ReferenceName("refs/heads/nonexistent")
+	err = dir.RemoveRef(name)
+	c.Assert(err, NotNil)
+
+	after, err := ioutil.ReadFile(filepath.Join(fs.Root(), packedRefsPath))
+	c.Assert(err, IsNil)
+
+	c.Assert(brokenContent, Equals, string(after))
+}
+
+func (s *SuiteDotGit) TestRemoveRefInvalidPackedRefs2(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	packedRefs := filepath.Join(fs.Root(), packedRefsPath)
+	brokenContent := strings.Repeat("a", bufio.MaxScanTokenSize*2)
+
+	err := ioutil.WriteFile(packedRefs, []byte(brokenContent), os.FileMode(0755))
+	c.Assert(err, IsNil)
+
+	name := plumbing.ReferenceName("refs/heads/nonexistent")
+	err = dir.RemoveRef(name)
+	c.Assert(err, NotNil)
+
+	after, err := ioutil.ReadFile(filepath.Join(fs.Root(), packedRefsPath))
+	c.Assert(err, IsNil)
+
+	c.Assert(brokenContent, Equals, string(after))
+}
+
+func (s *SuiteDotGit) TestRefsFromHEADFile(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+
+	ref := findReference(refs, "HEAD")
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Type(), Equals, plumbing.SymbolicReference)
+	c.Assert(string(ref.Target()), Equals, "refs/heads/master")
+}
+
+func (s *SuiteDotGit) TestConfig(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	file, err := dir.Config()
+	c.Assert(err, IsNil)
+	c.Assert(filepath.Base(file.Name()), Equals, "config")
+}
+
+func (s *SuiteDotGit) TestConfigWriteAndConfig(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.ConfigWriter()
+	c.Assert(err, IsNil)
+
+	_, err = f.Write([]byte("foo"))
+	c.Assert(err, IsNil)
+
+	f, err = dir.Config()
+	c.Assert(err, IsNil)
+
+	cnt, err := ioutil.ReadAll(f)
+	c.Assert(err, IsNil)
+
+	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)
+
+	file, err := dir.Shallow()
+	c.Assert(err, IsNil)
+	c.Assert(file, IsNil)
+}
+
+func (s *SuiteDotGit) TestShallowWriteAndShallow(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.ShallowWriter()
+	c.Assert(err, IsNil)
+
+	_, err = f.Write([]byte("foo"))
+	c.Assert(err, IsNil)
+
+	f, err = dir.Shallow()
+	c.Assert(err, IsNil)
+
+	cnt, err := ioutil.ReadAll(f)
+	c.Assert(err, IsNil)
+
+	c.Assert(string(cnt), Equals, "foo")
+}
+
+func findReference(refs []*plumbing.Reference, name string) *plumbing.Reference {
+	n := plumbing.ReferenceName(name)
+	for _, ref := range refs {
+		if ref.Name() == n {
+			return ref
+		}
+	}
+
+	return nil
+}
+
+func (s *SuiteDotGit) TestObjectPacks(c *C) {
+	f := fixtures.Basic().ByTag(".git").One()
+	fs := f.DotGit()
+	dir := New(fs)
+
+	hashes, err := dir.ObjectPacks()
+	c.Assert(err, IsNil)
+	c.Assert(hashes, HasLen, 1)
+	c.Assert(hashes[0], Equals, f.PackfileHash)
+
+	// Make sure that a random file in the pack directory doesn't
+	// break everything.
+	badFile, err := fs.Create("objects/pack/OOPS_THIS_IS_NOT_RIGHT.pack")
+	c.Assert(err, IsNil)
+	err = badFile.Close()
+	c.Assert(err, IsNil)
+
+	hashes2, err := dir.ObjectPacks()
+	c.Assert(err, IsNil)
+	c.Assert(hashes2, HasLen, 1)
+	c.Assert(hashes[0], Equals, hashes2[0])
+}
+
+func (s *SuiteDotGit) TestObjectPack(c *C) {
+	f := fixtures.Basic().ByTag(".git").One()
+	fs := f.DotGit()
+	dir := New(fs)
+
+	pack, err := dir.ObjectPack(f.PackfileHash)
+	c.Assert(err, IsNil)
+	c.Assert(filepath.Ext(pack.Name()), Equals, ".pack")
+}
+
+func (s *SuiteDotGit) TestObjectPackIdx(c *C) {
+	f := fixtures.Basic().ByTag(".git").One()
+	fs := f.DotGit()
+	dir := New(fs)
+
+	idx, err := dir.ObjectPackIdx(f.PackfileHash)
+	c.Assert(err, IsNil)
+	c.Assert(filepath.Ext(idx.Name()), Equals, ".idx")
+	c.Assert(idx.Close(), IsNil)
+}
+
+func (s *SuiteDotGit) TestObjectPackNotFound(c *C) {
+	fs := fixtures.Basic().ByTag(".git").One().DotGit()
+	dir := New(fs)
+
+	pack, err := dir.ObjectPack(plumbing.ZeroHash)
+	c.Assert(err, Equals, ErrPackfileNotFound)
+	c.Assert(pack, IsNil)
+
+	idx, err := dir.ObjectPackIdx(plumbing.ZeroHash)
+	c.Assert(err, Equals, ErrPackfileNotFound)
+	c.Assert(idx, IsNil)
+}
+
+func (s *SuiteDotGit) TestNewObject(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+	w, err := dir.NewObject()
+	c.Assert(err, IsNil)
+
+	err = w.WriteHeader(plumbing.BlobObject, 14)
+	c.Assert(err, IsNil)
+	n, err := w.Write([]byte("this is a test"))
+	c.Assert(err, IsNil)
+	c.Assert(n, Equals, 14)
+
+	c.Assert(w.Hash().String(), Equals, "a8a940627d132695a9769df883f85992f0ff4a43")
+
+	err = w.Close()
+	c.Assert(err, IsNil)
+
+	i, err := fs.Stat("objects/a8/a940627d132695a9769df883f85992f0ff4a43")
+	c.Assert(err, IsNil)
+	c.Assert(i.Size(), Equals, int64(34))
+}
+
+func (s *SuiteDotGit) TestObjects(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := New(fs)
+
+	hashes, err := dir.Objects()
+	c.Assert(err, IsNil)
+	c.Assert(hashes, HasLen, 187)
+	c.Assert(hashes[0].String(), Equals, "0097821d427a3c3385898eb13b50dcbc8702b8a3")
+	c.Assert(hashes[1].String(), Equals, "01d5fa556c33743006de7e76e67a2dfcd994ca04")
+	c.Assert(hashes[2].String(), Equals, "03db8e1fbe133a480f2867aac478fd866686d69e")
+}
+
+func (s *SuiteDotGit) TestObjectsNoFolder(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+	hash, err := dir.Objects()
+	c.Assert(err, IsNil)
+	c.Assert(hash, HasLen, 0)
+}
+
+func (s *SuiteDotGit) TestObject(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := New(fs)
+
+	hash := plumbing.NewHash("03db8e1fbe133a480f2867aac478fd866686d69e")
+	file, err := dir.Object(hash)
+	c.Assert(err, IsNil)
+	c.Assert(strings.HasSuffix(
+		file.Name(), fs.Join("objects", "03", "db8e1fbe133a480f2867aac478fd866686d69e")),
+		Equals, true,
+	)
+}
+
+func (s *SuiteDotGit) TestObjectNotFound(c *C) {
+	fs := fixtures.ByTag(".git").ByTag("unpacked").One().DotGit()
+	dir := New(fs)
+
+	hash := plumbing.NewHash("not-found-object")
+	file, err := dir.Object(hash)
+	c.Assert(err, NotNil)
+	c.Assert(file, IsNil)
+}
+
+func (s *SuiteDotGit) TestSubmodules(c *C) {
+	fs := fixtures.ByTag("submodule").One().DotGit()
+	dir := New(fs)
+
+	m, err := dir.Module("basic")
+	c.Assert(err, IsNil)
+	c.Assert(strings.HasSuffix(m.Root(), m.Join(".git", "modules", "basic")), Equals, true)
+}
+
+func (s *SuiteDotGit) TestPackRefs(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	fs := osfs.New(tmp)
+	dir := New(fs)
+
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/foo",
+		"e8d3ffab552895c19b9fcf7aa264d277cde33881",
+	), nil)
+	c.Assert(err, IsNil)
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/bar",
+		"a8d3ffab552895c19b9fcf7aa264d277cde33881",
+	), nil)
+	c.Assert(err, IsNil)
+
+	refs, err := dir.Refs()
+	c.Assert(err, IsNil)
+	c.Assert(refs, HasLen, 2)
+	looseCount, err := dir.CountLooseRefs()
+	c.Assert(err, IsNil)
+	c.Assert(looseCount, Equals, 2)
+
+	err = dir.PackRefs()
+	c.Assert(err, IsNil)
+
+	// Make sure the refs are still there, but no longer loose.
+	refs, err = dir.Refs()
+	c.Assert(err, IsNil)
+	c.Assert(refs, HasLen, 2)
+	looseCount, err = dir.CountLooseRefs()
+	c.Assert(err, IsNil)
+	c.Assert(looseCount, Equals, 0)
+
+	ref, err := dir.Ref("refs/heads/foo")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "e8d3ffab552895c19b9fcf7aa264d277cde33881")
+	ref, err = dir.Ref("refs/heads/bar")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "a8d3ffab552895c19b9fcf7aa264d277cde33881")
+
+	// Now update one of them, re-pack, and check again.
+	err = dir.SetRef(plumbing.NewReferenceFromStrings(
+		"refs/heads/foo",
+		"b8d3ffab552895c19b9fcf7aa264d277cde33881",
+	), nil)
+	c.Assert(err, IsNil)
+	looseCount, err = dir.CountLooseRefs()
+	c.Assert(err, IsNil)
+	c.Assert(looseCount, Equals, 1)
+	err = dir.PackRefs()
+	c.Assert(err, IsNil)
+
+	// Make sure the refs are still there, but no longer loose.
+	refs, err = dir.Refs()
+	c.Assert(err, IsNil)
+	c.Assert(refs, HasLen, 2)
+	looseCount, err = dir.CountLooseRefs()
+	c.Assert(err, IsNil)
+	c.Assert(looseCount, Equals, 0)
+
+	ref, err = dir.Ref("refs/heads/foo")
+	c.Assert(err, IsNil)
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "b8d3ffab552895c19b9fcf7aa264d277cde33881")
+}
+
+func (s *SuiteDotGit) TestAlternates(c *C) {
+	tmp, err := ioutil.TempDir("", "dot-git")
+	c.Assert(err, IsNil)
+	defer os.RemoveAll(tmp)
+
+	// Create a new billy fs.
+	fs := osfs.New(tmp)
+
+	// Create a new dotgit object and initialize.
+	dir := New(fs)
+	err = dir.Initialize()
+	c.Assert(err, IsNil)
+
+	// Create alternates file.
+	altpath := filepath.Join("objects", "info", "alternates")
+	f, err := fs.Create(altpath)
+	c.Assert(err, IsNil)
+
+	// Multiple alternates.
+	var strContent string
+	if runtime.GOOS == "windows" {
+		strContent = "C:\\Users\\username\\repo1\\.git\\objects\r\n..\\..\\..\\rep2\\.git\\objects"
+	} else {
+		strContent = "/Users/username/rep1//.git/objects\n../../../rep2//.git/objects"
+	}
+	content := []byte(strContent)
+	f.Write(content)
+	f.Close()
+
+	dotgits, err := dir.Alternates()
+	c.Assert(err, IsNil)
+	if runtime.GOOS == "windows" {
+		c.Assert(dotgits[0].fs.Root(), Equals, "C:\\Users\\username\\repo1\\.git")
+	} else {
+		c.Assert(dotgits[0].fs.Root(), Equals, "/Users/username/rep1/.git")
+	}
+
+	// For relative path:
+	// /some/absolute/path/to/dot-git -> /some/absolute/path
+	pathx := strings.Split(tmp, string(filepath.Separator))
+	pathx = pathx[:len(pathx)-2]
+	// Use string.Join() to avoid malformed absolutepath on windows
+	// C:Users\\User\\... instead of C:\\Users\\appveyor\\... .
+	resolvedPath := strings.Join(pathx, string(filepath.Separator))
+	// Append the alternate path to the resolvedPath
+	expectedPath := filepath.Join(string(filepath.Separator), resolvedPath, "rep2", ".git")
+	if runtime.GOOS == "windows" {
+		expectedPath = filepath.Join(resolvedPath, "rep2", ".git")
+	}
+	c.Assert(dotgits[1].fs.Root(), Equals, expectedPath)
+}