javascript - 如何让流程将两种字符串类型视为不兼容？

Question

我以前见过有人这样做过，但我不记得语法，而且我似乎在文档中找不到它。我基本上想让两种类型都解析为彼此不兼容的同一原语。一个例子应该很清楚，我希望流程使用此代码抛出错误:

type tUsername = string;
type tPassword = string;

function validateUser(user: tUsername, password: tPassword) {
}

validateUser(('foo': tPassword), ('bar': tUsername));

Answer 1

这里有很多相关内容 https://github.com/facebook/flow/issues/465

您可以使用不透明类型别名解决您的问题

Opaque type aliases are type aliases that do not allow access to their underlying type outside of the file in which they are defined.

https://flow.org/en/docs/types/opaque-types/