剩余元素必须位于元组类型的最后

Question

为cb写类型时：

const fn1 = (
  cb: (...args: [...args: any[], fn2: () => string, fn3: () => string]) => any,
  ...args: any[]
) => {
  const fn2 = () => 'fn2'
  const fn3 = () => 'fn3'
  cb(...args, fn2, fn3)
}

运行tsc，抛出错误：

A rest element must be last in a tuple type.

Answer 1

原来我一直在用全局的tsc，也就是v3.2.9，难怪我的行为跟别人不一样。当我切换到本地tsc即v4.2.3时，代码编译成功

剩余元素必须位于元组类型的最后

A rest element must be last in a tuple type

typescript

types

type-definition