func validateEventFunction()

in funcframework/events.go [168:184]

• 17 lines of code
• 5 McCabe index (conditional complexity)

func validateEventFunction(fn interface{}) error {
	ft := reflect.TypeOf(fn)
	if ft.NumIn() != 2 {
		return fmt.Errorf("expected function to have two parameters, found %d", ft.NumIn())
	}
	var err error
	errorType := reflect.TypeOf(&err).Elem()
	if ft.NumOut() != 1 || !ft.Out(0).AssignableTo(errorType) {
		return fmt.Errorf("expected function to return only an error")
	}
	var ctx context.Context
	ctxType := reflect.TypeOf(&ctx).Elem()
	if !ctxType.AssignableTo(ft.In(0)) {
		return fmt.Errorf("expected first parameter to be context.Context")
	}
	return nil
}