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Book: Browser Extension Book

  1. Introduction
  2. Understanding browser extensions. Setting up your development environment.
  3. Setting up a Node.js server with TypeScript, Express.js.
  4. User Authentication.
  5. Implementing stripe subscriptions.
  6. Adding LLM Feature and Deployment.

Chapter 2: Setting up a Node.js server with TypeScript, Express.js.

We keep our book up to date with recent libraries and packages.

The section below is a preview of Browser Extension Book. To read the full text, you will need to purchase the book.

In Chapter 2, you will start with the codebase in the 2-begin folder of our browser extension repo and end up with the codebase in the 2-end folder.

In this chapter, we'll discuss setting up a server for your Chrome extension using TypeScript, Express.js, and Yarn package manager.

We will cover the following topics in this chapter:

  • Why set up a server
  • Setting up a Node.js server with TypeScript, Express.js, and Yarn
  • Write server code
  • Compiling TypeScript Code and starting the server

Why set up a server? link

A server is essential for handling tasks that cannot be performed client-side, such as:

  1. Data Storage and Management:

    • Persistence: A server allows you to store user preferences, settings, or any other data persistently across sessions and devices. This ensures that user data remains intact even when they close the browser or switch devices.
    • Centralized Management: By centralizing data storage on the server, you can easily manage and manipulate data, ensuring consistency and integrity across different parts of your extension.
  2. User Authentication and Authorization:

    • Security: Implementing user authentication mechanisms on the server ensures that only authorized users can access certain features or data within the extension. This helps protect sensitive information and prevents unauthorized access.
    • Personalization: User authentication enables you to provide personalized experiences by customizing settings, content, or features based on individual user profiles.
  3. Integration with External Services:

    • Access to External APIs: A server facilitates integration with third-party APIs, allowing your extension to fetch data from external sources or perform actions on behalf of the user. This opens up possibilities for enriching your extension's functionality with external services.
    • Enhanced Features: By leveraging external APIs, you can enhance the capabilities of your extension, such as retrieving real-time data, accessing additional resources, or integrating with popular platforms and services.
  4. Background Processing and Task Execution:

    • Resource-intensive Tasks: Certain tasks, such as data processing or computations, may require more resources or processing power than what's available in the client-side environment. A server enables you to offload such tasks to the backend, ensuring efficient execution without impacting the user experience.
    • Asynchronous Operations: Background processing on the server allows your extension to perform asynchronous operations, such as sending notifications, processing large datasets, or handling long-running tasks, while the user continues to interact with the extension.
  5. Scalability and Performance:

    • Scalability: A server architecture provides scalability by allowing you to scale your infrastructure to accommodate a growing user base or increasing demand. You can add more server resources, such as additional servers or computing instances, to handle higher traffic loads and maintain optimal performance.
    • Optimized Performance: Offloading tasks to the server can improve the performance of your extension by reducing the workload on the client-side JavaScript environment. This results in faster response times, smoother interactions, and better overall user experience.
  6. Security and Compliance:

    • Data Security: Centralizing data storage and processing on the server enhances data security by implementing robust security measures, such as encryption, access controls, and data validation. This helps protect sensitive user information from unauthorized access or data breaches.
    • Regulatory Compliance: Implementing server-side security measures ensures compliance with regulatory requirements, such as data protection laws and industry standards. By adhering to compliance standards, you mitigate legal risks and build trust with users regarding data privacy and security.

Setting up a Node.js server with TypeScript, Express.js, and Yarn link

1. Let's change our current project folder structure

cd my-extension

Let's move our existing code from the chapter-1 to a separate folder called extension

2. Initialize a new node.js project with yarn

Create a new directory for your server-side code and initialize a new Node.js project using Yarn.

mkdir server
cd server
yarn init -y

3. Install dependencies

Install TypeScript, Express.js, and other required dependencies using Yarn.

yarn add typescript express
yarn add --dev @types/node @types/express nodemon ts-node
  • TypeScript is a programming language developed and maintained by Microsoft. It is a superset of JavaScript, which means any valid JavaScript code is also valid TypeScript code. TypeScript adds optional static typing to JavaScript, which can help catch errors early through type checking during development. This is particularly useful in large-scale applications where ensuring code quality and maintainability is crucial.

    TypeScript is compiled into plain JavaScript, which can be run in any browser, in Node.js, or in any JavaScript engine that supports ECMAScript 3 (or newer). This compilation step checks types and transpiles new JavaScript features down to older ones depending on the target specification.

  • Express.js is a fast, unopinionated, minimalist web framework for Node.js. It is used to build web applications and APIs. It simplifies routing, middleware integration, and many other server-side operations. This makes Express.js a popular choice for both serving web pages and handling RESTful API requests in a Node.js environment.

  • Nodemon is a utility that monitors for any changes in your source code files and automatically restarts your server. This is particularly useful during development as it saves time and effort in manually stopping and restarting your Node.js application whenever you make changes to the code.

    Nodemon is typically used in development environments and is not needed in production. It supports applications written in various languages but is most commonly used with Node.js applications.

  • TS-Node is a TypeScript execution engine and REPL for Node.js. It allows you to run TypeScript directly without having to compile it first into JavaScript. This simplifies the development process as you can execute scripts and directly see the results without an intermediate build step.

    TS-Node is mainly used in development environments for running scripts or interactive testing, and it integrates seamlessly with TypeScript's type checking features.

4. Create a src folder and configuration files

Create a src folder to store your TypeScript source files.

mkdir src

Create a tsconfig.json file in the root directory of your project.

  "compilerOptions": {
    "target": "es6",           // Specifies the ECMAScript target version: "ES6" (or ES2015). Code written in TypeScript will be compiled down to ES6.
    "module": "commonjs",      // Defines the module system, here "commonjs" which is common in Node.js environments.
    "outDir": "dist",          // Redirects output structure to the directory. Compiled files will be placed in the "dist" folder.
    "sourceMap": true,         // Enables the generation of sourcemaps, which help in debugging the TypeScript source code after it has been compiled to JavaScript.
    "esModuleInterop": true,   // Enables compatibility with Babel, allowing non-ES modules to be imported as default modules.
    "skipLibCheck": true       // Skips type checking of default library declaration files (like those of DOM or ES6).
  "include": ["src/**/*.ts"],  // This field specifies an array of filename patterns to include in the compilation. "src/**/*.ts" includes all TypeScript files in the "src" directory, recursively.
  "exclude": ["node_modules"]  // This field specifies an array of filename patterns to exclude from compilation. Typically, the "node_modules" folder is excluded to speed up the build process and avoid type checking for third-party libraries.

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We keep our book up to date with recent libraries and packages.