TypeScript Map类型中的回调函数隐式具有'any'类型,

jrcvhitl 于 9个月前发布在 TypeScript

关注(0)|答案(2)|浏览(120)

TypeScript版本： 2.9.0-dev.20180414
代码

declare function watch<T>(obj: T, propertyChangedCallbacks: { [K in keyof T]: (obj: T) => void }): void;
watch({ x: 0 }, {
    x: obj => {},
});

预期行为：

obj 是 { x: number } 。

实际行为：

src/a.ts(3,8): error TS7006: Parameter 'obj' implicitly has an 'any' type.

typescript

来源：https://github.com/microsoft/TypeScript/issues/23429

2条答案

按热度按时间

p1tboqfb1#

这也发生在2.8.1上：

type Events = {
  ready: () => void
  error: (e: Error) => void
  reconnecting: (params: { attempt: number, delay: number}) => void
}
type RedisClient = {
  on<E extends keyof Events>(event: E, f: Events[E]): void
}
let c: RedisClient
c.on('ready', () => 4)               // BAD - arity is propagated, return type is any
c.on('error', e => 4)                // BAD - e is any
c.on('reconnecting', p => p.attempt) // BAD - p is any