3 files changed, 208 insertions, 0 deletions
diff --git a/utils/fs/fs.go b/utils/fs/fs.go
new file mode 100644
index 0000000..df771dd
--- /dev/null
+++ b/utils/fs/fs.go
@@ -0,0 +1,21 @@
+package fs
+
+import (
+	"io"
+	"os"
+)
+
+// FS interface represent an abstracted filesystem, so you can
+// use NewRepositoryFromFS from any medium.
+type FS interface {
+	Stat(path string) (os.FileInfo, error)
+	Open(path string) (ReadSeekCloser, error)
+	ReadDir(path string) ([]os.FileInfo, error)
+	Join(elem ...string) string
+}
+
+// ReadSeekCloser is a Reader, Seeker and Closer.
+type ReadSeekCloser interface {
+	io.ReadCloser
+	io.Seeker
+}
diff --git a/utils/fs/os.go b/utils/fs/os.go
new file mode 100644
index 0000000..37ad75a
--- /dev/null
+++ b/utils/fs/os.go
@@ -0,0 +1,36 @@
+package fs
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+)
+
+// OS is a simple FS implementation for the current host filesystem.
+type OS struct{}
+
+// NewOS returns a new OS.
+func NewOS() FS {
+	return &OS{}
+}
+
+// Stat returns the filesystem info for a path.
+func (o *OS) Stat(path string) (os.FileInfo, error) {
+	return os.Stat(path)
+}
+
+// Open returns a ReadSeekCloser for the specified path.
+func (o *OS) Open(path string) (ReadSeekCloser, error) {
+	return os.Open(path)
+}
+
+// ReadDir returns the filesystem info for all the archives under the
+// specified path.
+func (o *OS) ReadDir(path string) ([]os.FileInfo, error) {
+	return ioutil.ReadDir(path)
+}
+
+// Join joins the specified elements using the filesystem separator.
+func (o *OS) Join(elem ...string) string {
+	return filepath.Join(elem...)
+}
diff --git a/utils/fs/os_test.go b/utils/fs/os_test.go
new file mode 100644
index 0000000..84fe895
--- /dev/null
+++ b/utils/fs/os_test.go
@@ -0,0 +1,151 @@
+package fs
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/alcortesm/tgz"
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type FSImplSuite struct {
+	dir string
+}
+
+var _ = Suite(&FSImplSuite{})
+
+func (s *FSImplSuite) SetUpSuite(c *C) {
+	dir, err := tgz.Extract("../../storage/seekable/internal/gitdir/fixtures/spinnaker-gc.tgz")
+	c.Assert(err, IsNil)
+	s.dir = dir
+}
+
+func (s *FSImplSuite) TearDownSuite(c *C) {
+	err := os.RemoveAll(s.dir)
+	c.Assert(err, IsNil)
+}
+
+func (s *FSImplSuite) TestJoin(c *C) {
+	fs := NewOS()
+	for i, test := range [...]struct {
+		input    []string
+		expected string
+	}{
+		{
+			input:    []string{},
+			expected: "",
+		}, {
+			input:    []string{"a"},
+			expected: "a",
+		}, {
+			input:    []string{"a", "b"},
+			expected: "a/b",
+		}, {
+			input:    []string{"a", "b", "c"},
+			expected: "a/b/c",
+		},
+	} {
+		obtained := fs.Join(test.input...)
+		com := Commentf("test %d:\n\tinput = %v", i, test.input)
+		c.Assert(obtained, Equals, test.expected, com)
+	}
+}
+
+func (s *FSImplSuite) TestStat(c *C) {
+	fs := NewOS()
+	for i, path := range [...]string{
+		".git/index",
+		".git/info/refs",
+		".git/objects/pack/pack-584416f86235cac0d54bfabbdc399fb2b09a5269.pack",
+	} {
+		path := fs.Join(s.dir, path)
+		com := Commentf("test %d", i)
+
+		real, err := os.Open(path)
+		c.Assert(err, IsNil, com)
+
+		expected, err := real.Stat()
+		c.Assert(err, IsNil, com)
+
+		obtained, err := fs.Stat(path)
+		c.Assert(err, IsNil, com)
+
+		c.Assert(obtained, DeepEquals, expected, com)
+
+		err = real.Close()
+		c.Assert(err, IsNil, com)
+	}
+}
+
+func (s *FSImplSuite) TestStatErrors(c *C) {
+	fs := NewOS()
+	for i, test := range [...]struct {
+		input     string
+		errRegExp string
+	}{
+		{
+			input:     "bla",
+			errRegExp: ".*bla: no such file or directory",
+		}, {
+			input:     "bla/foo",
+			errRegExp: ".*bla/foo: no such file or directory",
+		},
+	} {
+		com := Commentf("test %d", i)
+		_, err := fs.Stat(test.input)
+		c.Assert(err, ErrorMatches, test.errRegExp, com)
+	}
+}
+
+func (s *FSImplSuite) TestOpen(c *C) {
+	fs := NewOS()
+	for i, test := range [...]string{
+		".git/index",
+		".git/info/refs",
+		".git/objects/pack/pack-584416f86235cac0d54bfabbdc399fb2b09a5269.pack",
+	} {
+		com := Commentf("test %d", i)
+		path := fs.Join(s.dir, test)
+
+		real, err := os.Open(path)
+		c.Assert(err, IsNil, com)
+		realData, err := ioutil.ReadAll(real)
+		c.Assert(err, IsNil, com)
+		err = real.Close()
+		c.Assert(err, IsNil, com)
+
+		obtained, err := fs.Open(path)
+		c.Assert(err, IsNil, com)
+		obtainedData, err := ioutil.ReadAll(obtained)
+		c.Assert(err, IsNil, com)
+		err = obtained.Close()
+		c.Assert(err, IsNil, com)
+
+		c.Assert(obtainedData, DeepEquals, realData, com)
+	}
+}
+
+func (s *FSImplSuite) TestReadDir(c *C) {
+	fs := NewOS()
+	for i, test := range [...]string{
+		".git/info",
+		".",
+		"",
+		".git/objects",
+		".git/objects/pack",
+	} {
+		com := Commentf("test %d", i)
+		path := fs.Join(s.dir, test)
+
+		expected, err := ioutil.ReadDir(path)
+		c.Assert(err, IsNil, com)
+
+		obtained, err := fs.ReadDir(path)
+		c.Assert(err, IsNil, com)
+
+		c.Assert(obtained, DeepEquals, expected, com)
+	}
+}