fix(colors): truncate longer hex color values

Resolves https://vikunja.sentry.io/share/issue/6f1e37d4b8b248188e20650234a45cde/

pkg/models/task_collection_filter_test.go

@@ -17,13 +17,14 @@
 package models
 
 import (
-	"code.vikunja.io/api/pkg/db"
 	"testing"
 	"time"
-	"xorm.io/builder"
+
+	"code.vikunja.io/api/pkg/db"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"xorm.io/builder"
 )
 
 func TestParseFilter(t *testing.T) {

pkg/utils/normalize_hex.go

@@ -19,8 +19,10 @@ package utils
 import "strings"
 
 func NormalizeHex(hex string) string {
-	if strings.HasPrefix(hex, "#") {
-		return strings.TrimPrefix(hex, "#")
+	hex = strings.TrimPrefix(hex, "#")
+
+	if len(hex) > 6 {
+		return hex[:6]
 	}
 
 	return hex

pkg/utils/normalize_hex_test.go

@@ -0,0 +1,56 @@
+// Vikunja is a to-do list application to facilitate your life.
+// Copyright 2018-present Vikunja and contributors. All rights reserved.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public Licensee as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public Licensee for more details.
+//
+// You should have received a copy of the GNU Affero General Public Licensee
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package utils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNormalizeHex(t *testing.T) {
+	t.Run("no prefix", func(t *testing.T) {
+		normalized := NormalizeHex("fff000")
+
+		assert.Equal(t, "fff000", normalized)
+	})
+	t.Run("with # prefix", func(t *testing.T) {
+		normalized := NormalizeHex("#fff000")
+
+		assert.Equal(t, "fff000", normalized)
+	})
+	t.Run("longer than 6 chars with #", func(t *testing.T) {
+		normalized := NormalizeHex("#fff000SA")
+
+		assert.Equal(t, "fff000", normalized)
+	})
+	t.Run("longer than 6 chars", func(t *testing.T) {
+		normalized := NormalizeHex("fff000SA")
+
+		assert.Equal(t, "fff000", normalized)
+	})
+	t.Run("shorter than 6 chars with #", func(t *testing.T) {
+		normalized := NormalizeHex("#fff")
+
+		assert.Equal(t, "fff", normalized)
+	})
+	t.Run("shorter than 6 chars", func(t *testing.T) {
+		normalized := NormalizeHex("fff")
+
+		assert.Equal(t, "fff", normalized)
+	})
+}