core: fix nil pointer panic when deleting active grid meter (#32607)

core/site.go

@@ -881,7 +881,7 @@ func (site *Site) updateGridMeter() error {
 		return nil
 	}
 
-	mm := types.Measurement{Name: site.Meters.GridMeterRef}
+	mm := types.Measurement{Name: site.gridMeter.Config().Name}
 
 	meter := site.gridMeter.Instance()
 
@@ -935,7 +935,9 @@ func (site *Site) updateGridMeter() error {
 		}
 	}
 
-	site.collectors[site.Meters.GridMeterRef].AddEnergy(mm.Energy, mm.ReturnEnergy, mm.Power)
+	if c, ok := site.collectors[site.gridMeter.Config().Name]; ok {
+		c.AddEnergy(mm.Energy, mm.ReturnEnergy, mm.Power)
+	}
 
 	site.publish(keys.Grid, mm)
 

core/site_delete_test.go

@@ -0,0 +1,161 @@
+package core
+
+import (
+	"testing"
+	"time"
+
+	"github.com/evcc-io/evcc/api"
+	"github.com/evcc-io/evcc/core/keys"
+	"github.com/evcc-io/evcc/core/metrics"
+	"github.com/evcc-io/evcc/core/types"
+	"github.com/evcc-io/evcc/server/db"
+	"github.com/evcc-io/evcc/tariff"
+	"github.com/evcc-io/evcc/util"
+	"github.com/evcc-io/evcc/util/config"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+)
+
+// deleteTestSite mirrors what Prepare wires up: cached devices plus one energy
+// collector per meter, keyed by the meter's config name.
+type deleteTestSite struct {
+	*Site
+	params chan util.Param
+}
+
+func newDeleteTestSite(t *testing.T, ctrl *gomock.Controller) *deleteTestSite {
+	t.Helper()
+
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+	require.NoError(t, metrics.SetupSchema())
+
+	meter := func(power float64) api.Meter {
+		m := api.NewMockMeter(ctrl)
+		m.EXPECT().CurrentPower().Return(power, nil).AnyTimes()
+		return m
+	}
+
+	battery := func(power, soc float64) api.Meter {
+		m := api.NewMockMeter(ctrl)
+		m.EXPECT().CurrentPower().Return(power, nil).AnyTimes()
+		b := api.NewMockBattery(ctrl)
+		b.EXPECT().Soc().Return(soc, nil).AnyTimes()
+		return &struct {
+			api.Meter
+			api.Battery
+		}{Meter: m, Battery: b}
+	}
+
+	dev := func(name string, m api.Meter) config.Device[api.Meter] {
+		return config.NewStaticDevice(config.Named{Name: name}, m)
+	}
+
+	params := make(chan util.Param, 1024)
+
+	site := NewSite()
+	site.log = util.NewLogger("foo")
+	site.valueChan = params
+
+	site.gridMeter = dev("grid", meter(1e3))
+	site.pvMeters = []config.Device[api.Meter]{dev("pv", meter(2e3))}
+	site.batteryMeters = []config.Device[api.Meter]{dev("battery", battery(-500, 42))}
+
+	// collectors as Prepare registers them: keyed by the meter's config name
+	for _, c := range []struct{ group, name string }{
+		{metrics.Grid, "grid"},
+		{metrics.PV, "pv"},
+		{metrics.Battery, "battery"},
+		{metrics.Forecast, metrics.Forecast},
+		{metrics.Temperature, metrics.Temperature},
+	} {
+		col, err := metrics.NewCollector(c.group, c.name, c.name)
+		require.NoError(t, err)
+		site.collectors[c.name] = col
+	}
+
+	// site settings pointing at those meters
+	site.Meters.GridMeterRef = "grid"
+	site.Meters.PVMetersRef = []string{"pv"}
+	site.Meters.BatteryMetersRef = []string{"battery"}
+
+	return &deleteTestSite{Site: site, params: params}
+}
+
+// published drains the value channel and returns the last value per key
+func (s *deleteTestSite) published() map[string]any {
+	res := make(map[string]any)
+	for {
+		select {
+		case p := <-s.params:
+			res[p.Key] = p.Val
+		default:
+			return res
+		}
+	}
+}
+
+// TestSiteUpdateAfterMeterDeletion deletes the active grid, pv and battery meters while
+// running. Only the refs are cleared, the cached devices keep being polled (#32605).
+func TestSiteUpdateAfterMeterDeletion(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	s := newDeleteTestSite(t, ctrl)
+
+	// baseline: everything still referenced
+	require.NoError(t, s.updateGridMeter())
+	s.updatePvMeters()
+	s.updateBatteryMeters()
+
+	grid, ok := s.published()[keys.Grid].(types.Measurement)
+	require.True(t, ok, "grid measurement published")
+	assert.Equal(t, "grid", grid.Name, "grid measurement carries the meter name")
+
+	// delete all three meters- exactly what deleteDeviceHandler does to the site
+	s.SetGridMeterRef("")
+	s.SetPVMeterRefs(nil)
+	s.SetBatteryMeterRefs(nil)
+
+	require.NotPanics(t, func() {
+		require.NoError(t, s.updateGridMeter())
+		s.updatePvMeters()
+		s.updateBatteryMeters()
+	}, "update loop must survive the refs being cleared")
+
+	// the devices are still cached, so the loop keeps producing measurements
+	pub := s.published()
+	assert.Equal(t, 2e3, s.pvPower, "pv still polled")
+	assert.Equal(t, -500.0, s.battery.Power, "battery still polled")
+
+	grid, ok = pub[keys.Grid].(types.Measurement)
+	require.True(t, ok, "grid measurement still published")
+	assert.Equal(t, "grid", grid.Name, "grid measurement must keep the meter name, not the cleared ref")
+}
+
+// TestSiteUpdateAfterTariffDeletion deletes a tariff device. cleanupTariffRef only
+// rewrites the persisted refs, so the publish path must cope either way.
+func TestSiteUpdateAfterTariffDeletion(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	s := newDeleteTestSite(t, ctrl)
+
+	solar := api.NewMockTariff(ctrl)
+	solar.EXPECT().Type().Return(api.TariffTypeSolar).AnyTimes()
+	solar.EXPECT().Rates().Return(api.Rates{
+		{Start: time.Now().Add(-time.Hour), End: time.Now(), Value: 1e3},
+		{Start: time.Now(), End: time.Now().Add(time.Hour), Value: 2e3},
+	}, nil).AnyTimes()
+
+	s.tariffs = &tariff.Tariffs{Solar: solar}
+
+	require.NotPanics(t, func() {
+		s.publishTariffs(0, 0)
+	}, "tariff publish with a solar tariff")
+
+	require.NotNil(t, s.published()[keys.Forecast], "forecast published while the tariff exists")
+
+	// delete the tariff
+	s.tariffs = &tariff.Tariffs{}
+
+	require.NotPanics(t, func() {
+		s.publishTariffs(0, 0)
+	}, "tariff publish must survive the tariff being deleted")
+}