TypeScript extend JQuery under Namespace

Question

I'm trying to extend the default JQuery interface and the default object jQuery by a function in TypeScript

Code

/// <reference path="jquery.d.ts" />

namespace MyNameSpace {
    var $ = jQuery;
    export interface JQuery {
        test(options: Object): JQuery;
    }
    $.fn.test = function(options: Object): JQuery {
        if (this.length === 0) {
            console.log('Error!');
            return this;
        }
        console.log(options);
        return this;
    }
    export var testBody = function() {
        jQuery('body').test({ 'HELLO': 'TEST' });
    }
}

The Problem

Now I'm running the following code in my console: tsc -m amd -t ES5 Test.ts -d

I'm getting this error: Test.ts(17,19): error TS2339: Property 'test' does not exist on type 'JQuery'.

Any solution for this?

Answer 1

This works for me:

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

interface JQuery {
    test(options: Object): JQuery;
}

namespace MyNameSpace {
    var $ = jQuery;

    $.fn.test = function(options: Object): JQuery {
        if (this.length === 0) {
            console.log('Error!');
            return this;
        }
        console.log(options);
        return this;
    };
    export var testBody = function() {
        jQuery('body').test({ 'HELLO': 'TEST' });
    }
}

EDIT: 2nd solution

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

namespace MyNameSpace {

    interface JQueryX extends JQuery {
        test(options: Object): JQuery;
    }

    $.fn.test = function(options: Object): JQuery {
        if (this.length === 0) {
            console.log('Error!');
            return this;
        }
        console.log(options);
        return this;
    };

    export var testBody = function() {
        let a:JQueryX = <JQueryX>$('body');
        a.test({ 'HELLO': 'TEST' });
        // OR
        (<JQueryX>$('body')).test({ 'HELLO': 'TEST' });
    }
}

You can make the testBody nicer by some refactoring.