typescript - CustomError 类型的参数不能分配给 Typescript 中的错误

Question

为什么我的 typescript 引用我的自定义错误给我错误 Argument of type CustomError is not assignable to parameter of type Error in Typescript

我的错误类

module Errors {

    export declare class Error  {
            public name: string;
            public message: string;
            public stack: string;
            constructor(message?: string);
    }

    export class CustomError extends Error {
        constructor(message: string) {
            super(message);
            this.name = 'invalid parameters error';
            this.message = message || 'the parameters for the request or call are incorrect.';
            this.stack = (<any>new Error()).stack;
        }
    }
}

并在代码中从 Sequelize 返回一个 bluebird promise。

    var Promise = require('bluebird');
    var import Errors = require('./errors')

    //using fs here for an example, it can be any bluebird promise

    fs.readFileAsync("file.json").catch(Errors.InvalidParameterError, e => { //this is typescript compiler error
                return reply(Boom.badRequest())
            })

Answer 1

问题是 lib.d.ts 将 Error 声明为接口(interface)和变量，而不是类。

方案1.实现Error接口(interface)并通过util.inherits继承

import util = require('util');

module Errors {
    export class CustomError implements Error {
        name: string;
        message: string;

        constructor(message: string) {
            Error.call(this);
            Error.captureStackTrace(this, this.constructor);
            this.name = 'invalid parameters error';
            this.message = message || 'the parameters for the request or call are incorrect.';
        }
    }

    util.inherits(CustomError, Error);
}

export = Errors;

注意，captureStackTrace 没有在默认声明中声明，所以你应该在onw .d.ts 文件中声明它:

interface ErrorConstructor {
    captureStackTrace(error: Error, errorConstructor: Function);
}

选项2.不加类糖

module Errors {
    export var CustomError = <ErrorConstructor>function (message: string) {
        Error.call(this);
        Error.captureStackTrace(this, this.constructor);
        this.name = 'invalid parameters error';
        this.message = message || 'the parameters for the request or call are incorrect.';
    }

    util.inherits(CustomError, Error);
}

选项 3. 纯 TypeScript 方式

声明文件(不需要，因为鸭子打字):

declare type ErrorInterface = Error;

错误模块:

module Errors {
    declare class Error implements ErrorInterface {
        name: string;
        message: string;
        static captureStackTrace(object, objectConstructor?);
    }

    export class CustomError extends Error {
        constructor(message: string) {
            super();
            Error.captureStackTrace(this, this.constructor);
            this.name = 'invalid parameters error';
            this.message = message || 'the parameters for the request or call are incorrect.';
        }
    }
}

export = Errors;

同时检查您是否有正确的捕获声明:

catch(e: Error) // wrong
catch(e: { new (message?: string): Error }) // right