Track duplicate meter usage

cmd/config.go

@@ -73,11 +73,21 @@ type ConfigProvider struct {
 	meters   map[string]api.Meter
 	chargers map[string]api.Charger
 	vehicles map[string]api.Vehicle
+	visited  map[string]bool
 }
 
 // Meter provides meters by name
 func (cp *ConfigProvider) Meter(name string) api.Meter {
 	if meter, ok := cp.meters[name]; ok {
+		// track duplicate usage https://github.com/evcc-io/evcc/issues/1744
+		if cp.visited == nil {
+			cp.visited = make(map[string]bool)
+		}
+		if _, ok := cp.visited[name]; ok {
+			log.FATAL.Fatalf("duplicate meter usage: %s", name)
+		}
+		cp.visited[name] = true
+
 		return meter
 	}
 	log.FATAL.Fatalf("invalid meter: %s", name)

cmd/setup.go

@@ -30,7 +30,7 @@ func init() {
 	rand.Seed(time.Now().UnixNano())
 }
 
-var cp = &ConfigProvider{}
+var cp = new(ConfigProvider)
 
 func loadConfigFile(cfgFile string) (conf config, err error) {
 	if cfgFile != "" {