Config UI: allow disabling devices (#29455)

Co-authored-by: Michael Geers <michael@geers.tv>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: andig <184815+andig@users.noreply.github.com>

server/http_config_loadpoint_handler_test.go

@@ -0,0 +1,70 @@
+package server
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"strconv"
+	"testing"
+
+	"github.com/evcc-io/evcc/core/loadpoint"
+	"github.com/evcc-io/evcc/server/db"
+	"github.com/evcc-io/evcc/util/config"
+	"github.com/evcc-io/evcc/util/templates"
+	"github.com/gorilla/mux"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestLoadpointConfigDisabledNilInstance ensures loadpointConfig does not panic
+// for a disabled loadpoint whose instance was never created (nil loadpoint.API).
+func TestLoadpointConfigDisabledNilInstance(t *testing.T) {
+	conf := config.Config{
+		Class:      templates.Loadpoint,
+		Properties: config.Properties{Disable: true},
+		Data: map[string]any{
+			"charger": "wallbox",
+			"meter":   "lp-meter",
+			"title":   "Garage",
+		},
+	}
+
+	var instance loadpoint.API // nil: disabled loadpoint has no live instance
+	dev := config.NewConfigurableDevice(&conf, instance)
+
+	var res loadpointFullConfig
+	require.NotPanics(t, func() {
+		var err error
+		res, err = loadpointConfig(dev)
+		require.NoError(t, err)
+	})
+
+	assert.True(t, res.Disable)
+	assert.Equal(t, "wallbox", res.Charger)
+	assert.Equal(t, "lp-meter", res.Meter)
+}
+
+// TestDeleteLoadpointDisabledNilInstance ensures deleteLoadpointHandler does not
+// dereference a nil instance when deleting a disabled loadpoint.
+func TestDeleteLoadpointDisabledNilInstance(t *testing.T) {
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+
+	conf, err := config.AddConfig(templates.Loadpoint,
+		map[string]any{"charger": "wallbox", "title": "Garage"},
+		config.WithProperties(config.Properties{Disable: true}),
+	)
+	require.NoError(t, err)
+
+	var instance loadpoint.API // nil: disabled loadpoint has no live instance
+	dev := config.NewConfigurableDevice(&conf, instance)
+	require.NoError(t, config.Loadpoints().Add(dev))
+	t.Cleanup(func() { _ = config.Loadpoints().Delete(config.NameForID(conf.ID)) })
+
+	req := httptest.NewRequest(http.MethodDelete, "/", nil)
+	req = mux.SetURLVars(req, map[string]string{"id": strconv.Itoa(conf.ID)})
+	rec := httptest.NewRecorder()
+
+	require.NotPanics(t, func() {
+		deleteLoadpointHandler()(rec, req)
+	})
+	assert.Equal(t, http.StatusOK, rec.Code)
+}