打字稿：无效的“新”表达式答案

【问题标题】：Typescript: Invalid 'new' expression打字稿：无效的“新”表达式
【发布时间】：2014-08-11 22:17:17
【问题描述】：

为了帮助this person，我正在删除Ampersand.js 库的打字稿定义。给定以下打字稿代码，为什么编译器会输出 Invalid 'new' experession 错误？

[Here's a link to run the code using the typescript playground.]

declare module ampersand {
    interface AmpersandState {
        // todo...
    }

    interface AmpersandCollection {
        // todo...
    }

    interface ModelExtendOptions {
        parse?: boolean;
        parent?: AmpersandState;
        collection?: AmpersandCollection;
    }

    interface ModelSaveOptions {
        patch?: boolean;
    }

    class AmpersandModel<T> {
        constructor(attrs: T, options?: ModelExtendOptions);
        save: (attrs?: T, options?: ModelSaveOptions) => void;
        // todo:  fetch, destroy, sync, etc...
    }

    interface ExtendOptions {
        props?: {};
        session?: {};
        derived?: {};
    }   

    interface AmpersandModelStatic {
        extend: <T>(options: ExtendOptions) => AmpersandModel<T>;
    }
} 

declare var AmpersandModel: ampersand.AmpersandModelStatic;


interface PersonProps {
    firstName: string;
    lastName: string;
}

var Person = AmpersandModel.extend<PersonProps>({ props: { firstName: 'string', lastName: 'string' } });

var me = new Person({ firstName: 'Phil', lastName: 'Roberts' });

“新”表达式无效。

【问题讨论】：

标签： typescript ampersand

【解决方案1】：

我的扩展方法返回的是 AmpersandModel 的一个实例，而不是 ApersandModel 的构造函数。更正代码：

declare module ampersand {
    interface AmpersandState {
        // todo...
    }

    interface AmpersandCollection {
        // todo...
    }

    interface ModelExtendOptions {
        parse?: boolean;
        parent?: AmpersandState;
        collection?: AmpersandCollection;
    }

    interface ModelSaveOptions {
        patch?: boolean;
    }

    interface AmpersandModel<T> {
        save: (attrs?: T, options?: ModelSaveOptions) => void;
        // todo:  fetch, destroy, sync, etc...
    }

    interface AmpersandModelConstructor<T> {
        new (attrs: T, options?: ModelExtendOptions): AmpersandModel<T>;
    }   

    interface ExtendOptions {
        props?: {};
        session?: {};
        derived?: {};
    }   

    interface AmpersandModelStatic {
        extend: <T>(options: ExtendOptions) => AmpersandModelConstructor<T>;
    }
} 

declare var AmpersandModel: ampersand.AmpersandModelStatic;

interface PersonProps {
    firstName: string;
    lastName: string;
}

interface IPerson extends PersonProps, ampersand.AmpersandModel<PersonProps>{}

var Person = AmpersandModel.extend<PersonProps>({ props: { firstName: 'string', lastName: 'string' } });

var me = new Person({ firstName: 'Jeremy', lastName: 'Danyow' });

【讨论】：