tryz

Type-safe, composable programs with tracked errors and dependencies.

Overview

tryz is a lightweight TypeScript library for building programs where errors and dependencies are tracked at the type level. No more runtime surprises.

Features

• 🎯 Tracked errors — Know exactly what can fail at compile time
• 🔌 Tracked dependencies — Know exactly what's required to run
• 💉 Type-safe DI — Services resolved at runtime, verified at compile time
• 🔗 Composable — Chain, combine, and transform with full type inference
• 📦 Tiny — ~2KB minified, zero dependencies
• ⚡ Async-first — Seamless async/await integration

Installation

npm install tryz

Quick Start

import { x, Token, TypedError } from "tryz"

// Define a service token
class UserService extends Token("UserService")<{
	getUser: (id: string) => Promise<User>
}> {}

// Define a typed error
class NotFoundError extends TypedError("NotFound")<{
	resource: string
}> {}

// Create a program with typed dependencies and errors
const getUser = x.require(UserService).try(async (ctx) => {
	const user = await ctx.get(UserService).getUser("123")
	// Use x.fail() for type-safe errors
	if (!user) return x.fail(new NotFoundError({ resource: "user" }))
	return user
})
// Type: Program<User, NotFoundError, UserService>

// Provide dependencies and run
const result = await x.run(
	getUser.provide(x.provide(UserService, { getUser: fetchUser })),
)

// Result has discriminated union type
if (result.success) {
	console.log(result.value) // User
} else {
	console.error(result.error) // NotFoundError
}

Documentation

📖 Full Documentation

License

MIT © Matthew Wagerfield