如何在TypeScript中扩展宿主对象（例如，错误） [英] How do I extend a host object (e.g. Error) in TypeScript

问题描述

我想将主机对象错误扩展为自定义 UploadError 类。以下示例在编译时失败：

I would like to extend the host object Error to a custom UploadError class. The following example fails when I compile:

class UploadError extends Error {
    constructor(message: string, private code: number) {
        super(message);
    }

    getCode(): number {
        return this.code;
    }
}

当我运行TypeScript编译器时 tsc 我收到以下错误：

When I run the TypeScript compiler tsc I get the following error:

UploadError.ts(1,0): A export class may only extend other classes, Error is an interface.

似乎错误被定义为接口。如果有人知道实现的名称是什么，它会让我非常高兴： - ）

It seems Error is defined as an interface. If anyone knows what the name of the implementation is it would make me very happy :-)

function UploadError (message: string, code: number) {
    this.message = message;
    this.code = code;
}

UploadError.prototype = new Error();

UploadError.prototype.constructor = UploadError;

UploadError.prototype.getCode = (): number => {
    return this.code;
}

推荐答案

我找到了以下方法有效：

I have found the following approach works:

declare class ErrorClass implements Error {
    public name: string;
    public message: string;
    constructor(message?: string);
}
var ErrorClass = Error;

class MyError extends ErrorClass {
    public name = "MyError";
    constructor (public message?: string) {
        super(message);
    }
}

生成的脚本如下所示：

var ErrorClass = Error;
var MyError = (function (_super) {
    __extends(MyError, _super);
    function MyError(message) {
        _super.call(this, message);
        this.message = message;
        this.name = "MyError";
    }
    return MyError;
})(ErrorClass);

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