Plugins: allow setters to return nil (evcc-io#11442)

provider/go.go

@@ -167,6 +167,10 @@ func (p *Go) evaluate() (res any, err error) {
 		return nil, err
 	}
 
+	if v.IsNil() {
+		return nil, nil
+	}
+
 	return normalizeValue(v.Interface())
 }
 

provider/javascript.go

@@ -145,6 +145,10 @@ func (p *Javascript) evaluate() (any, error) {
 		return nil, err
 	}
 
+	if vv == nil {
+		return nil, nil
+	}
+
 	return normalizeValue(vv)
 }
 

provider/transformation.go

@@ -145,6 +145,10 @@ func transformInputs(in []inputTransformation, set func(string, any) error) erro
 
 func transformOutputs(out []outputTransformation, v any) error {
 	for _, cc := range out {
+		if v == nil {
+			return fmt.Errorf("no value to transform")
+		}
+
 		if err := cc.function(v); err != nil {
 			return fmt.Errorf("%s: %w", cc.name, err)
 		}