错误：* .default不是构造函数 [英] Error: *.default is not a constructor

问题描述

我在测试一些javascript代码时遇到以下错误，从一个打字稿文件中转换出来。

I get the following error, when testing some javascript code, transpiled from a typescript file.

这是错误：

Error: _mapAction2.default is not a constructor

以下是导致错误的代码行：

Here is the line of code that caused the error:

var mapAction = new MapAction(MapActionType.POLYGONDRAGGED, []);

这是原始的打字稿文件 map-action.ts ：

Here is the original typescript-file map-action.ts:

import { IMapAction} from './imap-action';
import { MapActionType } from './map-action-type.enum';
import {LatLngLiteral} from 'angular2-google-maps/core';

export class MapAction implements IMapAction{
    type: MapActionType;
    paths: Array<LatLngLiteral>;

    constructor(mapActionType: MapActionType, paths: Array<LatLngLiteral>){
        this.type = mapActionType;
        this.paths = paths;
    }

    public getType(): MapActionType{
        return this.type;
    }

    public getPaths(): Array<LatLngLiteral>
    {
        return this.paths;
    }

}

这是已编译的.js-文件 map-action.js ：

Here is the transpiled .js-file map-action.js:

"use strict";
class MapAction {
    constructor(mapActionType, paths) {
        this.type = mapActionType;
        this.paths = paths;
    }
    getType() {
        return this.type;
    }
    getPaths() {
        return this.paths;
    }
}
exports.MapAction = MapAction;
//# sourceMappingURL=map-action.js.map

推荐答案

您需要导出默认值，如下所示：

You need to export a default value which will look like:

export default class MapAction implements IMapAction {...

并将其导入为：

import MapAction from './map_action_file';

或者，如果你想从模块中导出多个的东西，你可以做类似的事情：

Alternatively, if you want to export multiple things from the module you can do something like:

export class MapAction ...
export class MapSomethng ...

并按如下方式导入：

import { MapAction, MapSomething } from './map_action_file';

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