Function validateReturns

lambda/handler.go:126–143

(handler reflect.Type)

}

func validateReturns(handler reflect.Type) error {
	errorType := reflect.TypeOf((*error)(nil)).Elem()

	switch n := handler.NumOut(); {
	case n > 2:
		return fmt.Errorf("handler may not return more than two values")
	case n > 1:
		if !handler.Out(1).Implements(errorType) {
			return fmt.Errorf("handler returns two values, but the second does not implement error")
		}
	case n == 1:
		if !handler.Out(0).Implements(errorType) {
			return fmt.Errorf("handler returns a single value, but it does not implement error")
		}
	}

	return nil
}

// NewHandler creates a base lambda handler from the given handler function. The
// returned Handler performs JSON serialization and deserialization, and