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Version: 0.2.0

Welcome to Super.js

Super.js is a strict, clean, and efficient superset of JavaScript that enforces ECMA standards with built-in type safety, formatting, linting, and testing capabilities.

What is Super.js?​

Super.js extends JavaScript with static type checking while maintaining pure JavaScript semantics. It provides TypeScript-like type safety with a focus on ECMA compliance and zero-configuration development experience.

Key Features​

  • Type Safety: Static type checking with JavaScript-first approach
  • Type Inference: Smart type inference based on ECMA standard patterns
  • Built-in Tooling: Integrated formatter, linter, and testing framework
  • Universal Compilation: Supports both frontend and backend environments
  • Zero Configuration: Works out of the box with sensible defaults
  • Fast Compilation: Optimized compilation process for quick development cycles
  • JavaScript Version Selection: Target specific JavaScript versions (ES5 to ES2022)
  • Native JSX Support: First-class JSX syntax support without external dependencies

Quick Start​

Installation​

npm install -g superjs

Creating a new project​

superjs init my-project
cd my-project

Your first Super.js file​

Create a file with the .sjs extension:

// hello.sjs
function greet(name: string): string {
  return `Hello, ${name}!`;
}

const message = greet("World");
console.log(message);

Compiling and running​

# Compile the file
superjs build --source hello.sjs

# Run the compiled JavaScript
node hello.js

File Extension​

Super.js files use the .sjs extension and support type annotations:

// example.sjs
interface User {
  name: string;
  age: number;
  email?: string; // Optional property
}

class UserAccount {
  constructor(public user: User) {}
  
  updateEmail(newEmail: string): void {
    this.user.email = newEmail;
  }
}

// Type inference
const numbers = [1, 2, 3]; // inferred as number[]
const user = {
  name: "John",
  age: 30
}; // inferred as { name: string, age: number }

JavaScript Version Targeting​

You can target specific JavaScript versions using the --target option:

# Target ES5
superjs build --source file.sjs --target es5

# Target ES2015 (ES6)
superjs build --source file.sjs --target es2015

# Target ES2020
superjs build --source file.sjs --target es2020

# Default (ES2022)
superjs build --source file.sjs

Supported JavaScript versions:

  • es5
  • es2015 (ES6)
  • es2016
  • es2017
  • es2018
  • es2019
  • es2020
  • es2021
  • es2022 (default)

Development Workflow​

Development mode with watch​

superjs dev

Running tests​

superjs test

Formatting code​

superjs format

Linting code​

superjs lint

What's Next?​