0xdevalias

Reverse Engineering Webpack Apps

Some notes and techniques for reverse engineering Webpack (and a little bit about React/Vue/Angular) apps.

Table of Contents

• Webpack (and similar bundlers) Chunk Format
  • AST Structure
• Basic minified example

jlouros

const AWS = require("aws-sdk"); // from AWS SDK
const fs = require("fs"); // from node.js
const path = require("path"); // from node.js

// configuration
const config = {
  s3BucketName: 'your.s3.bucket.name',
  folderPath: '../dist' // path relative script's location
};

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent