Refactor linker

fs.go

@@ -0,0 +1,70 @@
+// This file provides an interface and mocks to os functions used in dotbro.
+
+package main
+
+import "os"
+
+type DirMaker interface {
+	MkdirAll(path string, perm os.FileMode) error
+}
+
+type FakeDirMaker struct {
+	MkdirAllError error
+}
+
+func (f *FakeDirMaker) MkdirAll(path string, perm os.FileMode) error {
+	return f.MkdirAllError
+}
+
+type Symlinker interface {
+	Symlink(oldname, newname string) error
+}
+
+type FakeSymlinker struct {
+	SymlinkError error
+}
+
+func (f *FakeSymlinker) Symlink(oldname, newname string) error {
+	return f.SymlinkError
+}
+
+type Stater interface {
+	Stat(name string) (os.FileInfo, error)
+	IsNotExist(err error) bool
+}
+
+type MkdirSymlinker interface {
+	DirMaker
+	Symlinker
+}
+
+type FakeMkdirSymlinker struct {
+	*FakeDirMaker
+	*FakeSymlinker
+}
+
+type StatDirMaker interface {
+	Stater
+	DirMaker
+}
+
+// Actual implementation of interface using os package.
+
+type OsDirMaker struct {
+}
+
+func (f *OsDirMaker) MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+type OsSymlinker struct {
+}
+
+func (f *OsSymlinker) Symlink(oldname, newname string) error {
+	return os.Symlink(oldname, newname)
+}
+
+type OsMkdirSymlinker struct {
+	*OsDirMaker
+	*OsSymlinker
+}

helpers.go

@@ -5,11 +5,7 @@ import (
 	"path/filepath"
 )
 
-type Stater interface {
-	Stat(name string) (os.FileInfo, error)
-	IsNotExist(err error) bool
-}
-
+// TODO: remove in favor of StatDirMaker
 type DirCheckMaker interface {
 	Stater
 	MkdirAll(path string, perm os.FileMode) error

linker.go

@@ -6,6 +6,18 @@ import (
 	"path/filepath"
 )
 
+type Linker struct {
+	outputer IOutputer
+	fs       MkdirSymlinker
+}
+
+func NewLinker(outputer IOutputer, fs MkdirSymlinker) Linker {
+	return Linker{
+		outputer: outputer,
+		fs:       fs,
+	}
+}
+
 // needSymlink reports whether source file needs to be symlinked to destination path.
 func needSymlink(src, dest string) (bool, error) {
 	fi, err := os.Lstat(dest)
@@ -96,23 +108,18 @@ func backupCopy(filename, backupDir string) error {
 	return err
 }
 
-// setSymlink symlinks scrAbs to destAbs
-func setSymlink(srcAbs string, destAbs string) error {
-	var err error
-
-	// todo: if dry-run, just print
+// SetSymlink symlinks scrAbs to destAbs.
+func (l *Linker) SetSymlink(srcAbs string, destAbs string) error {
 
 	dir := path.Dir(destAbs)
-	err = os.MkdirAll(dir, 0700)
-	if err != nil {
+	if err := l.fs.MkdirAll(dir, 0700); err != nil {
 		return err
 	}
 
-	err = os.Symlink(srcAbs, destAbs)
-	if err != nil {
+	if err := l.fs.Symlink(srcAbs, destAbs); err != nil {
 		return err
 	}
 
-	outputer.OutInfo("  ✓ set symlink %s -> %s", srcAbs, destAbs)
+	l.outputer.OutInfo("  ✓ set symlink %s -> %s", srcAbs, destAbs)
 	return nil
 }

linker_test.go

@@ -1,10 +1,11 @@
 package main
 
 import (
-	"fmt"
+	"errors"
 	"io/ioutil"
 	"os"
 	"path"
+	"reflect"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -155,16 +156,67 @@ func TestBackupCopy(t *testing.T) {
 	assert.Equal(t, filenameContent, backupContent)
 }
 
-func TestSetSymlink(t *testing.T) {
+type FakeOutputer struct{}
 
-	os.RemoveAll("/tmp/dotbro") // Cleanup
+func (o *FakeOutputer) OutVerbose(format string, v ...interface{}) {
+	return
+}
 
-	srcAbs := "/tmp/dotbro/linker/TestSetSymlink/file"
-	destAbs := "/tmp/dotbro/linker/TestSetSymlink/filesymlink"
-	err := setSymlink(srcAbs, destAbs)
-	assert.Nil(t, err)
+func (o *FakeOutputer) OutInfo(format string, v ...interface{}) {
+	return
+}
+
+func (o *FakeOutputer) OutWarn(format string, v ...interface{}) {
+	return
+}
+
+func (o *FakeOutputer) OutError(format string, v ...interface{}) {
+	return
+}
+
+func TestNewLinker(t *testing.T) {
+	cases := []struct {
+		mkdirSymlinker *FakeMkdirSymlinker
+		srcAbs         string
+		destAbs        string
+		expectedError  error
+	}{
+		{
+			mkdirSymlinker: &FakeMkdirSymlinker{
+				&FakeDirMaker{MkdirAllError: nil},
+				&FakeSymlinker{SymlinkError: nil},
+			},
+			srcAbs:        "/src/path",
+			destAbs:       "/dest/path",
+			expectedError: nil,
+		},
+		{
+			mkdirSymlinker: &FakeMkdirSymlinker{
+				&FakeDirMaker{MkdirAllError: errors.New("Permission denied")},
+				&FakeSymlinker{SymlinkError: nil},
+			},
+			srcAbs:        "/src/path",
+			destAbs:       "/dest/path",
+			expectedError: errors.New("Permission denied"),
+		},
+		{
+			mkdirSymlinker: &FakeMkdirSymlinker{
+				&FakeDirMaker{MkdirAllError: nil},
+				&FakeSymlinker{SymlinkError: errors.New("File exists")},
+			},
+			srcAbs:        "/src/path",
+			destAbs:       "/dest/path",
+			expectedError: errors.New("File exists"),
+		},
+	}
+
+	for _, c := range cases {
+		linker := NewLinker(&FakeOutputer{}, c.mkdirSymlinker)
+
+		err := linker.SetSymlink(c.srcAbs, c.destAbs)
+		if !reflect.DeepEqual(err, c.expectedError) {
+			t.Errorf("Expected err to be %v but it was %v\n", c.expectedError, err)
+		}
+	}
 
-	// Calling again should return an error since the link already exists
-	err = setSymlink(srcAbs, destAbs)
-	assert.EqualError(t, err, fmt.Sprintf("symlink %s %s: file exists", srcAbs, destAbs))
 }

main.go

@@ -32,8 +32,9 @@ func (dcm *OsDirCheckMaker) MkdirAll(path string, perm os.FileMode) error {
 }
 
 var (
-	osStater        = new(OsStater)
-	osDirCheckMaker = new(OsDirCheckMaker)
+	osStater         = new(OsStater)
+	osDirCheckMaker  = new(OsDirCheckMaker)
+	osMkdirSymlinker = new(OsMkdirSymlinker)
 )
 
 func main() {
@@ -157,8 +158,10 @@ func addAction(filename string, config *Configuration) error {
 		return err
 	}
 
+	linker := NewLinker(&outputer, osMkdirSymlinker)
+
 	// Add a symlink to the moved file
-	if err = setSymlink(newPath, filename); err != nil {
+	if err = linker.SetSymlink(newPath, filename); err != nil {
 		return err
 	}
 
@@ -187,10 +190,11 @@ func installAction(config *Configuration) error {
 	}
 
 	mapping := getMapping(config, srcDirAbs)
+	linker := NewLinker(&outputer, osMkdirSymlinker)
 
 	outputer.OutInfo("Installing dotfiles...")
 	for src, dst := range mapping {
-		installDotfile(src, dst, config, srcDirAbs)
+		installDotfile(src, dst, linker, config, srcDirAbs)
 	}
 
 	return nil
@@ -285,7 +289,7 @@ func getMapping(config *Configuration, srcDirAbs string) map[string]string {
 	return mapping
 }
 
-func installDotfile(src, dest string, config *Configuration, srcDirAbs string) {
+func installDotfile(src, dest string, linker Linker, config *Configuration, srcDirAbs string) {
 	srcAbs := srcDirAbs + "/" + src
 	destAbs := config.Directories.Destination + "/" + dest
 
@@ -324,7 +328,7 @@ func installDotfile(src, dest string, config *Configuration, srcDirAbs string) {
 		}
 	}
 
-	err = setSymlink(srcAbs, destAbs)
+	err = linker.SetSymlink(srcAbs, destAbs)
 	if err != nil {
 		outputer.OutError("Error creating symlink from %s to %s: %s", srcAbs, destAbs, err)
 		exit(1)

outputer.go

@@ -13,6 +13,13 @@ const (
 	OutputerModeVerbose OutputerMode = "9"
 )
 
+type IOutputer interface {
+	OutVerbose(format string, v ...interface{})
+	OutInfo(format string, v ...interface{})
+	OutWarn(format string, v ...interface{})
+	OutError(format string, v ...interface{})
+}
+
 // Outputer is a logger that shows the output to the user.
 type Outputer struct {
 	Mode   OutputerMode