Chromium Extension Developer Guide

Introduction

This document provides essential information for developers working on our Chromium extension. It covers setup instructions, extension structure, and key development processes.

Getting Started

Prerequisites

  • Google Chrome or a Chromium-based browser

  • A code editor (e.g., Visual Studio Code, Sublime Text)

  • Basic knowledge of HTML, CSS, and JavaScript

Setup

  1. Clone the repository:

    git clone https://github.com/your-org/your-extension.git
cd your-extension

  2. Open Chrome and navigate to chrome://extensions

  3. Enable “Developer mode” in the top right corner

  4. Click “Load unpacked” and select your extension’s directory

Extension Structure

your-extension/
├── manifest.json
├── background.js
├── popup/
│   ├── popup.html
│   ├── popup.css
│   └── popup.js
├── content_scripts/
│   └── content.js
└── icons/
    ├── icon16.png
    ├── icon48.png
    └── icon128.png

Key Components

  • manifest.json: The extension’s configuration file

  • background.js: Background script for long-running tasks

  • popup/: Files for the extension’s popup UI

  • content_scripts/: Scripts that interact with web pages

  • icons/: Extension icons in various sizes

Development Workflow

Coding Standards

  • Follow JavaScript Standard Style for consistency

  • Use ES6+ features where appropriate

  • Keep functions small and focused

Testing

  1. Manual testing: - Load the extension in Chrome - Test all features thoroughly - Check for console errors

  2. Automated testing (if applicable): - Use Jest for unit testing - Run tests with:

    npm test

Debugging

  • Use console.log() for basic debugging

  • Utilize Chrome DevTools for advanced debugging: - Inspect popup: Right-click extension icon > Inspect popup - Debug background script: Go to chrome://extensions, click “background page” under your extension

Building and Publishing

Building the Extension

  1. Update manifest.json with the new version number

  2. Create a zip file of your extension directory

Publishing to Chrome Web Store

  1. Go to the Chrome Developer Dashboard

  2. Click “New Item” and upload your zip file

  3. Fill in all required fields (description, screenshots, etc.)

  4. Submit for review

API Reference

Chrome Extension APIs

Our extension primarily uses the following Chrome APIs:

  • chrome.runtime: For background script communication

  • chrome.tabs: For interacting with browser tabs

  • chrome.storage: For storing extension data

Custom Modules

// Example of documenting a custom module
/**
 * Utility functions for data processing
 * @module utils
 */

/**
 * Processes user data
 * @param {Object} data - The user data object
 * @returns {Object} Processed data
 */
function processUserData(data) {
  // Implementation details
}

Troubleshooting

Common Issues

  1. Issue: Extension not loading Solution: Ensure manifest.json is valid and all referenced files exist

  2. Issue: Content script not working Solution: Check if the content script is properly declared in manifest.json and matches the intended web pages

Getting Help

For additional assistance:

Change Log