扩展打字稿界面 [英] Extending typescript interface

问题描述

在TypeScript中扩展Express.Request接口时，我遇到了我想使用外部库定义的问题，但是由于导致错误->

When extending the Express.Request interface in TypeScript I ran into this problem that I want to use an external library definition, but I can't import the external library as it results in error ->

错误:(4，28)TS1147:内部模块中的导入声明无法引用外部模块.

Error:(4, 28) TS1147: Import declarations in an internal module cannot reference an external module.

这是一个.d.ts文件

It is a .d.ts file

/// <reference path="../typings/express/express.d.ts" />

declare module Express {
    import bunyan = require('bunyan'); <-- results in error
    export interface Request {
        _id: string; <-- this works
        log: bunyan.Logger; <-- Here I want to define that it is bunyan.Logger instance;
    }
}

尝试引用bunyan.d.ts( https: //github.com/borisyankov/DefinitelyTyped/blob/master/bunyan/bunyan.d.ts ) 由于将bunyan模块导出为字符串，因此也会导致问题

Trying to reference the bunyan.d.ts (https://github.com/borisyankov/DefinitelyTyped/blob/master/bunyan/bunyan.d.ts) Also results in a problem, as the bunyan module is exported as string

declare module "bunyan" {
...
}

如此一来，试图从参考中使用它就找不到了.

As such trying to use it from reference results in not found.

/// <reference path="../typings/express/express.d.ts" />
/// <reference path="../typings/bunyan/bunyan.d.ts" />

declare module Express {
    export interface Request {
        _id: string;
        log: bunyan.Logger; <- Error:(8, 18) TS2304: Cannot find name 'bunyan'.
    }
}

tl; dr;如何使用外部模块定义扩展接口定义.

tl;dr; How to extend interface definition with external module definitions.

推荐答案

我不认为您可以在需要require时添加到现有接口，但是可以使用extends关键字扩展现有接口

I don't think you can add to an existing interface when a require is necessary, but you can extend the existing interface using the extends keyword.

将import语句移至模块之外，导出模块，并扩展现有接口:

Move your import statement outside your module, export your module, and extend the existing interface:

import bunyan = require('bunyan');
import express = require('express');

export declare module ExtendedExpress {
    export interface Request extends express.Express.Request {
        _id: string;
        log: bunyan.Logger;
    }
}

然后，您必须将模块导入到要使用的位置.

Then you have to import this module where you want to use it.

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