Electron: app.on('ready') never gets called

I am trying to run electron app with TypeScript and webpack.
I have this main.ts file and compiled main.js file.

I edited main.js so that i can see if ready is called.

main.ts

import { app, BrowserWindow } from 'electron';
import * as url from 'url';
import * as path from 'path';

let win: Electron.BrowserWindow = null;


console.log('start');
console.log(app.isReady);
app.on('ready', () => {
  console.log('ready');
  win = new BrowserWindow({ width: 800, height: 600 });
  win.loadURL(url.format({
    pathname: path.join(__dirname, '../', 'no.html'),
    protocol: 'file:',
    slashes: true,
  }));
});

main.js

console.log('main.js -- start');
exports.ids = [3];
exports.modules = {

/***/ 18:
/***/ (function(module, exports, __webpack_require__) {

"use strict";

Object.defineProperty(exports, "__esModule", { value: true });
const electron_1 = __webpack_require__(19);
const url = __webpack_require__(20);
const path = __webpack_require__(21);
let win = null;
console.log('before ready');
electron_1.app.on('ready', () => {
    console.log('ready');
    win = new electron_1.BrowserWindow({ width: 800, height: 600 });
    win.loadURL(url.format({
        pathname: path.join(__dirname, '../', 'index.html'),
        protocol: 'file:',
        slashes: true,
    }));
});


/***/ }),

/***/ 19:
/***/ (function(module, exports) {

module.exports = require("electron");

/***/ }),

/***/ 20:
/***/ (function(module, exports) {

module.exports = require("url");

/***/ }),

/***/ 21:
/***/ (function(module, exports) {

module.exports = require("path");

/***/ })

};;
console.log('main.js -- finish');

When I run ./node_modules/.bin/electron . , my console shows

> electron .

main.js -- start
main.js -- finish

And nothing happens. no window will be opened.

Here is my folder structure.

.
├── build
│   ├── index.js
│   └── main.js
├── index.html
├── package.json
├── src
│   ├── index.ts
│   └── main.ts
└── webpack.config.js

Also I wrote "main": "build/main.js", on my package.son file.

My environments

OS: Mac 10.10.5
electron: 1.6.11
node: v8.2.1
webpack: 3.0.0

Thank you for reading. I will appreciate any help!!

P.S. Here is my webpack config file.

const path = require('path');
const webpack = require('webpack');
module.exports = {
  entry: {
    main: './src/main.ts',
    index: './src/index.ts',
    template: './src/memo.vue',
    memo: './src/memo.vue'
  },
  output: {
    path: __dirname + '/build',
    filename: '[name].js'
  },
  plugins: [
    new webpack.optimize.CommonsChunkPlugin({
      name: 'common'
    })
  ],
  target: 'electron-main',
  resolve: {
    extensions: ['.ts', '.vue', '.js'],
    modules: ["node_modules"],
    alias: {
      vue: 'vue/dist/vue.js'
    }
  },
  module: {
    rules: [
      {
        test: /\.ts$/,
        include: [path.resolve(__dirname, 'src')],
        exclude: [path.resolve(__dirname, 'node_modules')],
        loader: 'ts-loader'
      },
      {
        test: /\.vue$/,
        include: [path.resolve(__dirname, 'src')],
        exclude: [path.resolve(__dirname, 'node_modules')],
        loader: 'vue-loader'
      }
      ,
      {
        test: /\.ts$/,
        include: [path.resolve(__dirname, 'src')],
        exclude: [path.resolve(__dirname, 'node_modules')],
        enforce: 'pre',
        loader: 'tslint-loader',
        options: {
          fix: true
        }
      }
    ]
  },
  node: {
    __dirname: false
  }
}