是否可以约束jsDoc @template声明中定义的泛型类型? [英] Is it possible to constrain a generic type defined in a jsDoc @template declaration?

问题描述

我们想使用jsDoc注释在常规.js文件中定义 mixin类而不是.ts文件.

We'd like to define mixin classes in regular .js files using jsDoc comments instead of .ts files.

mixin类的一个重要方面是使用extends将泛型类型参数限制为类构造函数.例如，以上页面具有以下TypeScript:

An important aspect of mixin classes is constraining the generic type parameter to a class constructor using extends. E.g., the above page has the following TypeScript:

type Constructor<T> = new(...args: any[]) => T;
function Tagged<T extends Constructor<{}>>(Base: T) { ... }

TypeScript的jsDoc支持允许@template T声明，但是我们看不到任何将T约束为例如类构造函数的方法.有什么方法可以做到吗?

TypeScript's jsDoc support allows for a @template T declaration, but we don't see any way to constrain T to, for example, be a class constructor. Is there some way to do that?

我们愿意创建/使用.d.ts文件来支持此操作，只要mixin声明本身可以存在于.js文件中，并且checkJs将适当地对该文件的类型进行检查. js文件.

We'd be willing to create/use .d.ts files to support this, as long as the mixin declaration itself can exist in a .js file, and that checkJs will appropriately type-check the workings of that .js file.

推荐答案

从TypeScript 2.9开始，现在似乎可以使用TypeScript来约束模板参数(请参见

As of TypeScript 2.9 it seems constraining template parameters is now possible using TypeScript (see issue 24600). The above TypeScript declaration would therefor become:

/**
 * @template T
 * @typedef {new(...args: any[]) => T} Constructor
 **/

/**
 * @template {Constructor<{}>} T
 * @param {T} Base
 */
function Tagged(Base) { … }

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