Slugs: Use base32 encoding for slugs that don't contain text photoprism#4761

Signed-off-by: Michael Mayer <michael@photoprism.app>

Author: lastzero

pkg/txt/slug.go

@@ -1,11 +1,17 @@
 package txt
 
 import (
+	"encoding/base32"
 	"strings"
 
 	"github.com/gosimple/slug"
 )
 
+const SlugCharset = "abcdefghijklmnopqrstuvwxyz123456"
+const SlugEncoded = '_'
+
+var SlugEncoding = base32.NewEncoding(SlugCharset).WithPadding(base32.NoPadding)
+
 // Slug converts a string to a valid slug with a max length of 80 runes.
 func Slug(s string) string {
 	s = strings.TrimSpace(s)
@@ -14,7 +20,13 @@ func Slug(s string) string {
 		return ""
 	}
 
-	return Clip(slug.Make(s), ClipSlug)
+	result := slug.Make(s)
+
+	if result == "" {
+		result = string(SlugEncoded) + SlugEncoding.EncodeToString([]byte(s))
+	}
+
+	return Clip(result, ClipSlug)
 }
 
 // SlugToTitle converts a slug back to a title
@@ -23,5 +35,13 @@ func SlugToTitle(s string) string {
 		return ""
 	}
 
+	if s[0] == SlugEncoded {
+		title, err := SlugEncoding.DecodeString(s[1:])
+
+		if len(title) > 0 && err == nil {
+			return string(title)
+		}
+	}
+
 	return Title(strings.Join(Words(s), " "))
 }

pkg/txt/slug_test.go

@@ -10,7 +10,7 @@ func TestSlug(t *testing.T) {
 	t.Run("Empty", func(t *testing.T) {
 		assert.Equal(t, "", Slug(""))
 	})
-	t.Run("BillGates", func(t *testing.T) {
+	t.Run("Gates", func(t *testing.T) {
 		assert.Equal(t, "william-henry-gates-iii", Slug("William  Henry Gates III"))
 	})
 	t.Run("Quotes", func(t *testing.T) {
@@ -19,13 +19,26 @@ func TestSlug(t *testing.T) {
 	t.Run("Chinese", func(t *testing.T) {
 		assert.Equal(t, "chen-zhao", Slug(" 陈  赵"))
 	})
+	t.Run("Emoji", func(t *testing.T) {
+		assert.Equal(t, "_5cpzfdq", Slug("💎"))
+		assert.Equal(t, "_5cpzfea", Slug("💐"))
+		assert.Equal(t, "_5cpzfea", Slug("   💐   "))
+		assert.Equal(t, "_5cpzfdxqt5jja", Slug("💎💐"))
+		assert.Equal(t, "photoprism", Slug("PhotoPrism 💎"))
+	})
 }
 
 func TestSlugToTitle(t *testing.T) {
-	t.Run("cute_Kitten", func(t *testing.T) {
+	t.Run("Empty", func(t *testing.T) {
+		assert.Equal(t, "", SlugToTitle(""))
+	})
+	t.Run("Kitten", func(t *testing.T) {
 		assert.Equal(t, "Cute-Kitten", SlugToTitle("cute-kitten"))
 	})
-	t.Run("empty", func(t *testing.T) {
-		assert.Equal(t, "", SlugToTitle(""))
+	t.Run("Emoji", func(t *testing.T) {
+		assert.Equal(t, "💎", SlugToTitle("_5cpzfdq"))
+		assert.Equal(t, "💐", SlugToTitle("_5cpzfea"))
+		assert.Equal(t, "💎💐", SlugToTitle("_5cpzfdxqt5jja"))
+		assert.Equal(t, "PhotoPrism", SlugToTitle("photoprism"))
 	})
 }