diff --git a/docopt.go b/docopt.go
index 6dd4b3e..1af4a7c 100644
--- a/docopt.go
+++ b/docopt.go
@@ -4,7 +4,8 @@ import "github.com/docopt/docopt-go"
 
 const version = "0.2.0"
 
-func parseArguments() (map[string]interface{}, error) {
+// ParseArguments parses arguments, that were passed to the dotbro, by docopt.
+func ParseArguments(argv []string) (map[string]interface{}, error) {
 	usage := `dotbro - simple yet effective dotfiles manager.
 
 Usage:
@@ -27,5 +28,5 @@ Other options:
   -V --version            Show version.
 `
 
-	return docopt.Parse(usage, nil, true, "dotbro "+version, false)
+	return docopt.Parse(usage, argv, true, "dotbro "+version, false)
 }
diff --git a/docopt_test.go b/docopt_test.go
new file mode 100644
index 0000000..bc4a6cf
--- /dev/null
+++ b/docopt_test.go
@@ -0,0 +1,10 @@
+package main
+
+import "testing"
+
+func TestParseArguments(t *testing.T) {
+	_, err := ParseArguments([]string{"--quiet"})
+	if err != nil {
+		t.Fatalf("Error parsing arguments: %v", err.Error())
+	}
+}
diff --git a/fs.go b/fs.go
index 9f56c9f..c55e64d 100644
--- a/fs.go
+++ b/fs.go
@@ -4,6 +4,19 @@ package main
 
 import "os"
 
+// Intefaces
+
+type OS interface {
+	MkdirAll(path string, perm os.FileMode) error
+
+	Symlink(oldname, newname string) error
+
+	Stat(name string) (os.FileInfo, error)
+	IsNotExist(err error) bool
+
+	Rename(oldpath, newpath string) error
+}
+
 type DirMaker interface {
 	MkdirAll(path string, perm os.FileMode) error
 }
@@ -17,9 +30,9 @@ type Stater interface {
 	IsNotExist(err error) bool
 }
 
-type FakeMkdirSymlinker struct {
-	*FakeDirMaker
-	*FakeSymlinker
+type MkdirSymlinker interface {
+	DirMaker
+	Symlinker
 }
 
 type StatDirMaker interface {
@@ -27,8 +40,41 @@ type StatDirMaker interface {
 	DirMaker
 }
 
+type Renamer interface {
+	Rename(oldpath, newpath string) error
+}
+
 // Fake implementation of interface
 
+type FakeOS struct {
+	MkdirAllError    error
+	SymlinkError     error
+	StatFileInfo     os.FileInfo
+	StatError        error
+	IsNotExistResult bool
+	RenameError      error
+}
+
+func (f *FakeOS) MkdirAll(path string, perm os.FileMode) error {
+	return f.MkdirAllError
+}
+
+func (f *FakeOS) Symlink(oldname, newname string) error {
+	return f.SymlinkError
+}
+
+func (f *FakeOS) Stat(name string) (os.FileInfo, error) {
+	return f.StatFileInfo, f.StatError
+}
+
+func (f *FakeOS) IsNotExist(err error) bool {
+	return f.IsNotExistResult
+}
+
+func (f *FakeOS) Rename(oldname, newname string) error {
+	return f.RenameError
+}
+
 type FakeDirMaker struct {
 	MkdirAllError error
 }
@@ -59,13 +105,48 @@ func (f *FakeStater) IsNotExist(err error) bool {
 	return f.IsNotExistResult
 }
 
-type MkdirSymlinker interface {
-	DirMaker
-	Symlinker
+type FakeMkdirSymlinker struct {
+	*FakeDirMaker
+	*FakeSymlinker
+}
+
+type FakeStatDirMaker struct {
+	*FakeStater
+	*FakeDirMaker
+}
+
+type FakeRenamer struct {
+	RenameError error
+}
+
+func (f *FakeRenamer) Rename(oldpath, newpath string) error {
+	return f.RenameError
 }
 
 // Actual implementation of interface using os package.
 
+type OSFS struct{}
+
+func (f *OSFS) MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+func (f *OSFS) Symlink(oldname, newname string) error {
+	return os.Symlink(oldname, newname)
+}
+
+func (s *OSFS) Stat(name string) (os.FileInfo, error) {
+	return os.Stat(name)
+}
+
+func (s *OSFS) IsNotExist(err error) bool {
+	return os.IsNotExist(err)
+}
+
+func (f *OSFS) Rename(oldpath, newpath string) error {
+	return os.Rename(oldpath, newpath)
+}
+
 type OsDirMaker struct {
 }
 
@@ -79,11 +160,6 @@ func (f *OsSymlinker) Symlink(oldname, newname string) error {
 	return os.Symlink(oldname, newname)
 }
 
-type OsMkdirSymlinker struct {
-	*OsDirMaker
-	*OsSymlinker
-}
-
 type OsStater struct{}
 
 func (s *OsStater) Stat(name string) (os.FileInfo, error) {
@@ -93,3 +169,19 @@ func (s *OsStater) Stat(name string) (os.FileInfo, error) {
 func (s *OsStater) IsNotExist(err error) bool {
 	return os.IsNotExist(err)
 }
+
+type OsMkdirSymlinker struct {
+	*OsDirMaker
+	*OsSymlinker
+}
+
+type OsStatDirMaker struct {
+	*OsStater
+	*OsDirMaker
+}
+
+type OsRenamer struct{}
+
+func (f *OsRenamer) Rename(oldpath, newpath string) error {
+	return os.Rename(oldpath, newpath)
+}
diff --git a/linker.go b/linker.go
index b2903e4..0243acc 100644
--- a/linker.go
+++ b/linker.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"path"
 	"path/filepath"
@@ -8,13 +9,13 @@ import (
 
 type Linker struct {
 	outputer IOutputer
-	fs       MkdirSymlinker
+	os       OS
 }
 
-func NewLinker(outputer IOutputer, fs MkdirSymlinker) Linker {
+func NewLinker(outputer IOutputer, os OS) Linker {
 	return Linker{
 		outputer: outputer,
-		fs:       fs,
+		os:       os,
 	}
 }
 
@@ -71,19 +72,26 @@ func needBackup(dest string) (bool, error) {
 	return false, nil
 }
 
-// backup copies existing destination file to backup dir.
-func backup(dest string, destAbs string, backupDir string) error {
+// Move moves oldpath to newpath, creating target directories if need.
+func (l *Linker) Move(oldpath, newpath string) error {
 	// todo: if dry-run, just print
 
-	dir := path.Dir(backupDir + "/" + dest)
-	err := os.MkdirAll(dir, 0700)
+	// check if destination file exists
+	exists, err := IsExists(l.os, oldpath)
+	if err != nil {
+		return err
+	}
+	if !exists {
+		return fmt.Errorf("File %s not exists", oldpath)
+	}
+
+	err = l.os.MkdirAll(path.Dir(newpath), 0700)
 	if err != nil {
 		return err
 	}
 
-	backupPath := backupDir + "/" + dest
-	outputer.OutVerbose("  → backup %s to %s", destAbs, backupPath)
-	err = os.Rename(destAbs, backupPath)
+	l.outputer.OutVerbose("  → backup %s to %s", oldpath, newpath)
+	err = l.os.Rename(oldpath, newpath)
 	return err
 }
 
@@ -112,11 +120,11 @@ func backupCopy(filename, backupDir string) error {
 func (l *Linker) SetSymlink(srcAbs string, destAbs string) error {
 
 	dir := path.Dir(destAbs)
-	if err := l.fs.MkdirAll(dir, 0700); err != nil {
+	if err := l.os.MkdirAll(dir, 0700); err != nil {
 		return err
 	}
 
-	if err := l.fs.Symlink(srcAbs, destAbs); err != nil {
+	if err := l.os.Symlink(srcAbs, destAbs); err != nil {
 		return err
 	}
 
diff --git a/linker_test.go b/linker_test.go
index 5677b43..d8f1f55 100644
--- a/linker_test.go
+++ b/linker_test.go
@@ -117,23 +117,61 @@ func TestNeedBackup(t *testing.T) {
 	assert.False(t, actual)
 }
 
-func TestBackup(t *testing.T) {
-
-	os.RemoveAll("/tmp/dotbro") // Cleanup
-
-	dest := "new"
-	destAbs := "/tmp/dotbro/linker/TestBackup/new"
-	backupDir := "/tmp/dotbro/linker/TestBackup/backup"
+func TestMove(t *testing.T) {
+	cases := []struct {
+		os            *FakeOS
+		oldpath       string
+		newpath       string
+		expectedError error
+	}{
+		{
+			// Failure when IsExists fails
+			os: &FakeOS{
+				StatError: errors.New("Some error"),
+			},
+			expectedError: errors.New("Some error"),
+		},
+		{
+			// Failure when dest file not exists
+			os: &FakeOS{
+				IsNotExistResult: true,
+			},
+			oldpath:       "/path/dest",
+			expectedError: errors.New("File /path/dest not exists"),
+		},
+		{
+			// Failure when MkdirAll fails
+			os: &FakeOS{
+				IsNotExistResult: false,
+				MkdirAllError:    errors.New("MkdirAll error"),
+			},
+			expectedError: errors.New("MkdirAll error"),
+		},
+		{
+			// Failure when Rename fails
+			os: &FakeOS{
+				IsNotExistResult: false,
+				RenameError:      errors.New("Rename error"),
+			},
+			expectedError: errors.New("Rename error"),
+		},
+		{
+			// Success
+			os: &FakeOS{
+				IsNotExistResult: false,
+			},
+			expectedError: nil,
+		},
+	}
 
-	err := backup(dest, destAbs, backupDir)
-	assert.Error(t, err)
+	for _, c := range cases {
+		linker := NewLinker(&FakeOutputer{}, c.os)
+		err := linker.Move(c.oldpath, c.newpath)
 
-	err = os.MkdirAll(destAbs, 0700)
-	if err != nil {
-		t.Fatal(err)
+		if !reflect.DeepEqual(err, c.expectedError) {
+			t.Errorf("Expected err to be %v but it was %v\n", c.expectedError, err)
+		}
 	}
-	err = backup(dest, destAbs, backupDir)
-	assert.Empty(t, err)
 }
 
 func TestBackupCopy(t *testing.T) {
@@ -176,33 +214,33 @@ func (o *FakeOutputer) OutError(format string, v ...interface{}) {
 
 func TestNewLinker(t *testing.T) {
 	cases := []struct {
-		mkdirSymlinker *FakeMkdirSymlinker
+		os *FakeOS
 		srcAbs         string
 		destAbs        string
 		expectedError  error
 	}{
 		{
-			mkdirSymlinker: &FakeMkdirSymlinker{
-				&FakeDirMaker{MkdirAllError: nil},
-				&FakeSymlinker{SymlinkError: nil},
+			os: &FakeOS{
+				MkdirAllError: nil,
+				SymlinkError: nil,
 			},
 			srcAbs:        "/src/path",
 			destAbs:       "/dest/path",
 			expectedError: nil,
 		},
 		{
-			mkdirSymlinker: &FakeMkdirSymlinker{
-				&FakeDirMaker{MkdirAllError: errors.New("Permission denied")},
-				&FakeSymlinker{SymlinkError: nil},
+			os: &FakeOS{
+				MkdirAllError: errors.New("Permission denied"),
+				SymlinkError: nil,
 			},
 			srcAbs:        "/src/path",
 			destAbs:       "/dest/path",
 			expectedError: errors.New("Permission denied"),
 		},
 		{
-			mkdirSymlinker: &FakeMkdirSymlinker{
-				&FakeDirMaker{MkdirAllError: nil},
-				&FakeSymlinker{SymlinkError: errors.New("File exists")},
+			os: &FakeOS{
+				MkdirAllError: nil,
+				SymlinkError: errors.New("File exists"),
 			},
 			srcAbs:        "/src/path",
 			destAbs:       "/dest/path",
@@ -211,7 +249,7 @@ func TestNewLinker(t *testing.T) {
 	}
 
 	for _, c := range cases {
-		linker := NewLinker(&FakeOutputer{}, c.mkdirSymlinker)
+		linker := NewLinker(&FakeOutputer{}, c.os)
 
 		err := linker.SetSymlink(c.srcAbs, c.destAbs)
 		if !reflect.DeepEqual(err, c.expectedError) {
diff --git a/main.go b/main.go
index ca705c8..144babf 100644
--- a/main.go
+++ b/main.go
@@ -17,6 +17,7 @@ var (
 	osStater         = new(OsStater)
 	osDirMaker       = new(OsDirMaker)
 	osMkdirSymlinker = new(OsMkdirSymlinker)
+	osfs             = new(OSFS)
 )
 
 func main() {
@@ -28,7 +29,7 @@ func main() {
 
 	// Parse arguments
 
-	args, err := parseArguments()
+	args, err := ParseArguments(nil)
 	if err != nil {
 		outputer.OutError("Error parsing aruments: %s", err)
 		exit(1)
@@ -133,13 +134,13 @@ func addAction(filename string, config *Configuration) error {
 		return fmt.Errorf("Cannot backup file %s: %s", filename, err)
 	}
 
-	// move file to dotfiles root
+	// Move file to dotfiles root
 	newPath := config.Directories.Dotfiles + "/" + path.Base(filename)
 	if err = os.Rename(filename, newPath); err != nil {
 		return err
 	}
 
-	linker := NewLinker(&outputer, osMkdirSymlinker)
+	linker := NewLinker(&outputer, osfs)
 
 	// Add a symlink to the moved file
 	if err = linker.SetSymlink(newPath, filename); err != nil {
@@ -171,7 +172,7 @@ func installAction(config *Configuration) error {
 	}
 
 	mapping := getMapping(config, srcDirAbs)
-	linker := NewLinker(&outputer, osMkdirSymlinker)
+	linker := NewLinker(&outputer, osfs)
 
 	outputer.OutInfo("Installing dotfiles...")
 	for src, dst := range mapping {
@@ -302,9 +303,11 @@ func installDotfile(src, dest string, linker Linker, config *Configuration, srcD
 	}
 
 	if needBackup {
-		err = backup(dest, destAbs, config.Directories.Backup)
+		oldpath := destAbs
+		newpath := config.Directories.Backup + "/" + dest
+		err = linker.Move(oldpath, newpath)
 		if err != nil {
-			outputer.OutError("Error backuping file %s: %s", destAbs, err)
+			outputer.OutError("Error on file backup %s: %s", oldpath, err)
 			exit(1)
 		}
 	}