Turn shortener.Shortener into an interface

And have the default shortener be Base58Shortener.

shortener/base58_shortener.go

@@ -0,0 +1,87 @@
+package shortener
+
+import (
+	"crypto/sha1"
+	"fmt"
+
+	"github.com/jimeh/go-base58"
+	"github.com/jimeh/ozu.io/storage"
+)
+
+var urlKeyPrefix = []byte("url:")
+var uidKeyPrefix = []byte("uid:")
+
+// NewBase58 returns a new *Base58Shortner that uses the given storage.Store.
+func NewBase58(store storage.Store) *Base58Shortener {
+	return &Base58Shortener{Store: store}
+}
+
+// Base58Shortener shortens URLs via base 58 encoding.
+type Base58Shortener struct {
+	Store storage.Store
+}
+
+// Shorten a given URL.
+func (s *Base58Shortener) Shorten(rawURL []byte) (uid []byte, url []byte, err error) {
+	url, err = NormalizeURL(rawURL)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	urlKey := s.makeURLKey(url)
+	uid, err = s.Store.Get(urlKey)
+
+	if uid != nil && err == nil {
+		return uid, url, nil
+	} else if err != nil && err.Error() != "not found" {
+		return nil, nil, err
+	}
+
+	uid, err = s.newUID()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	err = s.Store.Set(urlKey, uid)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	uidKey := s.makeUIDKey(uid)
+	err = s.Store.Set(uidKey, url)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return uid, url, nil
+}
+
+// Lookup the URL of a given UID.
+func (s *Base58Shortener) Lookup(uid []byte) ([]byte, error) {
+	uidKey := s.makeUIDKey(uid)
+
+	url, err := s.Store.Get(uidKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return url, nil
+}
+
+func (s *Base58Shortener) newUID() ([]byte, error) {
+	index, err := s.Store.NextSequence()
+	if err != nil {
+		return nil, err
+	}
+
+	return base58.Encode(index), nil
+}
+
+func (s *Base58Shortener) makeUIDKey(uid []byte) []byte {
+	return append(uidKeyPrefix, uid...)
+}
+
+func (s *Base58Shortener) makeURLKey(rawURL []byte) []byte {
+	urlSHA := fmt.Sprintf("%x", sha1.Sum(rawURL))
+	return append(urlKeyPrefix, urlSHA...)
+}

shortener/base58_shortener_test.go

@@ -17,22 +17,22 @@ import (
 
 // Suite Setup
 
-type ShortenerSuite struct {
+type Base58ShortenerSuite struct {
 	suite.Suite
 	store       *mocks.Store
-	shortener   *Shortener
+	shortener   *Base58Shortener
 	errNotFound error
 }
 
-func (s *ShortenerSuite) SetupTest() {
+func (s *Base58ShortenerSuite) SetupTest() {
 	s.store = new(mocks.Store)
-	s.shortener = New(s.store)
+	s.shortener = NewBase58(s.store)
 	s.errNotFound = errors.New("not found")
 }
 
 // Tests
 
-func (s *ShortenerSuite) TestShortenExisting() {
+func (s *Base58ShortenerSuite) TestShortenExisting() {
 	rawURL := []byte("http://google.com/")
 	uid := []byte("ig")
 	urlSHA := fmt.Sprintf("%x", sha1.Sum(rawURL))
@@ -46,7 +46,7 @@ func (s *ShortenerSuite) TestShortenExisting() {
 	s.store.AssertExpectations(s.T())
 }
 
-func (s *ShortenerSuite) TestShortenNew() {
+func (s *Base58ShortenerSuite) TestShortenNew() {
 	rawURL := []byte("https://google.com")
 	url := []byte("https://google.com/")
 	uid := []byte("ig")
@@ -65,7 +65,7 @@ func (s *ShortenerSuite) TestShortenNew() {
 	s.store.AssertExpectations(s.T())
 }
 
-func (s *ShortenerSuite) TestShortenInvalidURL() {
+func (s *Base58ShortenerSuite) TestShortenInvalidURL() {
 	examples := []struct {
 		url   string
 		error string
@@ -100,7 +100,7 @@ func (s *ShortenerSuite) TestShortenInvalidURL() {
 	}
 }
 
-func (s *ShortenerSuite) TestShortenStoreError() {
+func (s *Base58ShortenerSuite) TestShortenStoreError() {
 	url := []byte("https://google.com/")
 	storeErr := errors.New("leveldb: something wrong")
 	urlKey := append([]byte("url:"), fmt.Sprintf("%x", sha1.Sum(url))...)
@@ -113,7 +113,7 @@ func (s *ShortenerSuite) TestShortenStoreError() {
 	s.EqualError(err, storeErr.Error())
 }
 
-func (s *ShortenerSuite) TestLookupExisting() {
+func (s *Base58ShortenerSuite) TestLookupExisting() {
 	url := []byte("https://google.com/")
 	uid := []byte("ig")
 
@@ -126,7 +126,7 @@ func (s *ShortenerSuite) TestLookupExisting() {
 	s.store.AssertExpectations(s.T())
 }
 
-func (s *ShortenerSuite) TestLookupNonExistant() {
+func (s *Base58ShortenerSuite) TestLookupNonExistant() {
 	uid := []byte("ig")
 
 	s.store.On("Get", append([]byte("uid:"), uid...)).Return(nil, s.errNotFound)
@@ -141,5 +141,5 @@ func (s *ShortenerSuite) TestLookupNonExistant() {
 // Run Suite
 
 func TestShortenerSuite(t *testing.T) {
-	suite.Run(t, new(ShortenerSuite))
+	suite.Run(t, new(Base58ShortenerSuite))
 }

shortener/new.go

@@ -0,0 +1,8 @@
+package shortener
+
+import "github.com/jimeh/ozu.io/storage"
+
+// New returns a new *Base58Shortner that uses the given storage.Store.
+func New(store storage.Store) Shortener {
+	return NewBase58(store)
+}

shortener/shortener.go

@@ -1,87 +1,7 @@
 package shortener
 
-import (
-	"crypto/sha1"
-	"fmt"
-
-	"github.com/jimeh/go-base58"
-	"github.com/jimeh/ozu.io/storage"
-)
-
-// New returns a new *Shortner that uses the given storage.Store.
-func New(store storage.Store) *Shortener {
-	return &Shortener{Store: store}
-}
-
-var urlKeyPrefix = []byte("url:")
-var uidKeyPrefix = []byte("uid:")
-
-// Shortner interface
-type Shortener struct {
-	Store storage.Store
-}
-
-// Shorten a given URL.
-func (s *Shortener) Shorten(rawURL []byte) (uid []byte, url []byte, err error) {
-	url, err = NormalizeURL(rawURL)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	urlKey := s.makeURLKey(url)
-	uid, err = s.Store.Get(urlKey)
-
-	if uid != nil && err == nil {
-		return uid, url, nil
-	} else if err != nil && err.Error() != "not found" {
-		return nil, nil, err
-	}
-
-	uid, err = s.newUID()
-	if err != nil {
-		return nil, nil, err
-	}
-
-	err = s.Store.Set(urlKey, uid)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	uidKey := s.makeUIDKey(uid)
-	err = s.Store.Set(uidKey, url)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	return uid, url, nil
-}
-
-// Lookup the URL of a given UID.
-func (s *Shortener) Lookup(uid []byte) ([]byte, error) {
-	uidKey := s.makeUIDKey(uid)
-
-	url, err := s.Store.Get(uidKey)
-	if err != nil {
-		return nil, err
-	}
-
-	return url, nil
-}
-
-func (s *Shortener) newUID() ([]byte, error) {
-	index, err := s.Store.NextSequence()
-	if err != nil {
-		return nil, err
-	}
-
-	return base58.Encode(index), nil
-}
-
-func (s *Shortener) makeUIDKey(uid []byte) []byte {
-	return append(uidKeyPrefix, uid...)
-}
-
-func (s *Shortener) makeURLKey(rawURL []byte) []byte {
-	urlSHA := fmt.Sprintf("%x", sha1.Sum(rawURL))
-	return append(urlKeyPrefix, urlSHA...)
+// Shortener defines a shortener interface for shortening URLs.
+type Shortener interface {
+	Shorten([]byte) ([]byte, []byte, error)
+	Lookup([]byte) ([]byte, error)
 }