Result.js — Rust-inspired Result Type

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A lightweight, Rust-inspired Result type for Javascript and Typescript. Handle success and error cases explicitly without exceptions.

Features

• 🦀 Rust-inspired API - Familiar Result<T, E> pattern
• 🎯 Type-safe - Full Typescript support with excellent inference
• 📦 Zero dependencies - Lightweight and focused
• 🔗 Chainable - Fluent API with map, andThen, and more
• ⚡ Tree-shakeable - Optimized bundle size
• 🛡 No exceptions - Safe error handling without try-catch

Quick Start

Installation

npm install @eriveltonsilva/result.js

Import

// ES6 - Recommended
import { Result } from '@eriveltonsilva/result.js'

// ES6 - Default Import
import Result from '@eriveltonsilva/result.js'

// CommonJS
const { Result } = require('@eriveltonsilva/result.js')

Basic Usage

// Create Results
const success = Result.ok(42)
const failure = Result.err(new Error('Something went wrong'))

// Check and unwrap
if (success.isOk()) {
  console.log(success.unwrap()) // 42
}

// Chain operations
const doubled = Result.ok(21)
  .map((x) => x * 2)
  .andThen((x) => Result.ok(x + 10))
  .unwrap() // 52

// Pattern matching
const result = Result.ok(42)
  .match({
    ok: (value) => value * 2,
    err: (error) => error.message,
  }) // 84

// Handle errors safely
const result = Result.fromTry(
  () => JSON.parse('invalid'),
  (error) => new Error(`Invalid JSON: ${error}`)
) // Error: Invalid JSON: SyntaxError: Unexpected token, "invalid" is not valid JSON

Documentation

For comprehensive guides, API reference, and advanced usage patterns, see the complete documentation.

Learn more:

• Quick Start
• Examples
• API Reference

Changelog

See CHANGELOG.md for a detailed list of changes in each release.

Contributing

Contributions are welcome! Please read our Contributing Guide for details.

License

MIT © Erivelton Silva

Inspiration

Inspired by:

• Rust's Result type
• Gleam Result Type
• oxide.ts
• result.ts