Question

我有以下文字编码:

function loader<P extends [], T>(load: (...args: P) => Promise<T>, lazy = false) {
    const result: { value?: T, error?: unknown } = {}
    function start(...args: P) {
        load(...args)
            .then(v => result.value = v)
            .catch(e => result.error = e)
    }

    // Argument of type  []  is not assignable to parameter of type  P .
    if (!lazy) start()

    return { restart: start, result }
}

const load = (a = 1, b = 2) => Promise.resolve(a + b)

// restart is () => void
const { restart, result } = loader(load)

我需要限制参数<代码><<>载荷/代码>,以便能够在没有参数的情况下使用,即没有参数,或者所有参数都是选择性的。功能<代码>start。

此外,我希望restart和load有相同的参数清单。页: 1 应为(a?: number, b?: number) => Promise< number>。

Answer 1

考虑以下守则:

const a = [1, 2, 3];
const b: [] = a;

你可以看到以下错误信息:

Type  number[]  is not assignable to type  [] .
  Target allows only 0 element(s) but source may have more.

实际上,<代码>[a?: number hexachloro> Defin, b?: number > un Defin] not lif []/code>。


Instead of <P extends [], T>, use <P extends any[], T> to solve this issue.
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