Browserify project with tsify

build.js

var gulp = require("gulp");
var browserify = require("browserify");
var babelify = require("babelify");
var source = require("vinyl-source-stream");
var config = {
    src: "index.js",
    filename: "bundle.js",
    dest: "./"
};
var extensions = ['.js', '.ts', '.json'];
var b = browserify({extensions: extensions});
b
    .plugin('tsify', {target: 'es6'})
    .transform(babelify.configure({
        extensions: extensions
    }))
    .add(config.src)
    .bundle()
    // log errors if they happen
    .on("error", function(e){
        console.log(e.message);
        throw e;
    })
    .pipe(source(config.filename))
    .pipe(gulp.dest(config.dest));

ctrl.ts

export default class Ctrl {
    name: string;
    constructor(name: string){
        this.name = name;
    }
    login() {
        return "Hello, " + this.name;
    }
}

index.js

import Ctrl from './ctrl.ts';

let ctrl = new Ctrl("Dolly");
console.log(ctrl.login());

tsconfig.json

{
    "compilerOptions": {
        "module": "commonjs",
        "noImplicitAny": true,
        "target": "es6"
    }
}