[英]Unable to define class type in Typescript
I'm attempting to define a 'Definition' type in Typescript.我试图在 Typescript 中定义一个“定义”类型。 A Definition can be either a class constructor or an object - such that later I do:定义可以是类构造函数或对象 - 稍后我会这样做:
if (this._isConstructor(definition)) {
return new definition(...args); // is a class - instantiate it
}
return definition; // is just an object - return it
I have my type defined as:我的类型定义为:
type Definition = {
new (arg?: object): object | object
}
which seems to work.这似乎有效。 However, it looks ugly and I want to split it out into:但是,它看起来很丑,我想将其拆分为:
type Definition = {
Cstruct | object
}
type Cstruct = new (arg?: object): object
however that then moans that然而那然后呻吟着
Cannot use 'new' with an expression whose type lacks a call or construct signature不能对类型缺少调用或构造签名的表达式使用“new”
when trying to 'new' it.当试图“新”它时。
A solution using a type guard :使用类型保护的解决方案:
type Definition = Cstruct | object
type Cstruct = {new (arg?: object): object}
function isConstructor(def: Definition): def is Cstruct {
// Here implement your test and return true or false
return true
}
function getObject(def: Definition, args = []) {
if (isConstructor(def))
return new definition(...args);
return def;
}
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