扩展“通用"TypeScript 接口 [英] Extending 'generic' TypeScript interface

问题描述

考虑以下 TS 定义:

Considering following TS definition:

type GenericPropsWithChildren<T> = T & { children?: ReactNode };

type 没有问题，但我想知道是否有等效的 interface ?显然，可以将泛型向下传递到接口，尽管这不是我所追求的，例如.:

Nothing wrong with type but I wonder if there is an interface equivalent? Obviously it is possible to pass generics down into interfaces though that is not what I am after, e. g.:

interface GenericPropsWithChildren<T> {
 children?: ReactNode;
 myProps: T; // not desired
}

这里的示例是在 React 代码的上下文中，但潜在的问题是基本的 TS.

The examples here are in a context of React code but the underlying issue is fundamental TS.

推荐答案

在声明时必须知道接口的成员，在扩展中使用泛型类型参数违反了此规则.所以没有办法创建等效的通用接口.

An interface's members must be known at declaration, using a generic type parameter in the extends violates this rule. So there is no way to create an equivalent generic interface.

如果您已经知道类型参数，您实际上可以在接口中继承类型别名.只要在声明时知道所有成员，就允许:

If you already know the type parameter you can actually inherit a type alias in an interface. As long as all members are known at declaration it is allowed :

import { ReactNode } from 'react'

type GenericPropsWithChildren<T> = T & { children?: ReactNode };

interface Concrete extends GenericPropsWithChildren<{ p: string }> {

}

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