fix: device color MQTT encoding (#30168)

ui/colors.go

@@ -3,15 +3,22 @@ package ui
 
 import (
 	"maps"
+	"slices"
+	"strings"
 	"sync"
 
 	"github.com/evcc-io/evcc/core/keys"
 	"github.com/evcc-io/evcc/server/db/settings"
 )
 
+// DeviceColor is the MQTT-safe publish format (map keys would leak into topic segments).
+type DeviceColor struct {
+	Title string `json:"title"`
+	Color string `json:"color"`
+}
+
 var colorsMu sync.RWMutex
 
-// GetDeviceColors returns the persisted title→hex map (never nil).
 func GetDeviceColors() map[string]string {
 	colorsMu.RLock()
 	defer colorsMu.RUnlock()
@@ -20,7 +27,6 @@ func GetDeviceColors() map[string]string {
 	return m
 }
 
-// SaveDeviceColors persists the title→hex map.
 func SaveDeviceColors(m map[string]string) error {
 	colorsMu.Lock()
 	defer colorsMu.Unlock()
@@ -28,3 +34,13 @@ func SaveDeviceColors(m map[string]string) error {
 	maps.Copy(clean, m)
 	return settings.SetJson(keys.DeviceColors, clean)
 }
+
+func DeviceColorList() []DeviceColor {
+	m := GetDeviceColors()
+	list := make([]DeviceColor, 0, len(m))
+	for title, color := range m {
+		list = append(list, DeviceColor{Title: title, Color: color})
+	}
+	slices.SortFunc(list, func(a, b DeviceColor) int { return strings.Compare(a.Title, b.Title) })
+	return list
+}

ui/colors_test.go

@@ -0,0 +1,45 @@
+package ui
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/evcc-io/evcc/server/db"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func setupDB(t *testing.T) {
+	t.Helper()
+	require.NoError(t, db.NewInstance("sqlite", filepath.Join(t.TempDir(), "test.db")))
+}
+
+func TestDeviceColors_RoundTrip(t *testing.T) {
+	setupDB(t)
+
+	in := map[string]string{"WP-SG+": "#2563EB", "Heizung": "#DC2626"}
+	require.NoError(t, SaveDeviceColors(in))
+
+	assert.Equal(t, in, GetDeviceColors())
+}
+
+func TestDeviceColors_EmptyWhenAbsent(t *testing.T) {
+	setupDB(t)
+	assert.Empty(t, GetDeviceColors())
+}
+
+func TestDeviceColorList_SortedAndSafe(t *testing.T) {
+	setupDB(t)
+
+	require.NoError(t, SaveDeviceColors(map[string]string{
+		"WP-SG+":  "#2563EB",
+		"Heizung": "#DC2626",
+		"Carport": "#10B981",
+	}))
+
+	assert.Equal(t, []DeviceColor{
+		{Title: "Carport", Color: "#10B981"},
+		{Title: "Heizung", Color: "#DC2626"},
+		{Title: "WP-SG+", Color: "#2563EB"},
+	}, DeviceColorList())
+}