Question

在TypeScript手册中，这是declaration merging：

的示例

// observable.js
export class Observable<T> {
    // ... implementation left as an exercise for the reader ...
}

// map.ts
import { Observable } from "./observable";
declare module "./observable" {
    interface Observable<T> {
        map<U>(f: (x: T) => U): Observable<U>;
    }
}
Observable.prototype.map = function (f) {
    // ... another exercise for the reader
}

// consumer.ts
import { Observable } from "./observable";
import "./map";
let o: Observable<number>;
o.map(x => x.toFixed());

由于Webpack编译了我的TypeScript代码，我可以使用npm模块xstream，它带有this类型定义：

import {Stream, MemoryStream, Listener, Producer, Operator} from './core';
export {Stream, MemoryStream, Listener, Producer, Operator};
export default Stream;

我可以像这样使用它（map是一种有效的方法）：

// consumer.ts
import { Stream } from "xstream";
let s: Stream<number>;
s.map(x => x);

我想扩展Stream界面并尝试类似官方示例。所以在我的情况下，它是"xstream"而不是"./observable"，我的扩展名在 extensions.ts 文件中，而不是 map.ts ：

// extensions.ts
import { Stream } from "xstream";
declare module "xstream" {
  interface Stream<T> {
    foo(): Stream<T>;
  }
}

Stream.prototype.foo = function foo() {
  console.log('foo');
  return this;
};

// consumer.ts
import { Stream } from "xstream";
import "./extensions";
let s: Stream<number>;
s.foo().map(x => x);

可悲的是，我收到了多个错误：

ERROR in [default] <path to my project>/node_modules/xstream/index.d.ts:2:9
Export declaration conflicts with exported declaration of 'Stream'

ERROR in [default] <path to my project>/src/extendingExistingModule/extensions.ts:8:0
Cannot find name 'Stream'.

ERROR in [default] <path to my project>/src/extendingExistingModule/index.ts:5:8
Property 'map' does not exist on type 'Stream<number>'.

我该如何修复它们？

使用过的版本

typescript@2.0.0
xstream@5.3.2

TypeScript：如何扩展npm模块的类型定义？

0 个答案: