mauss

a lightweight and modular utility library for writing declarative, type-safe code

A focused set of modular, type-safe functions for writing compact declarative code.

Installation

pnpm add mauss

Why?

The best of both worlds

1. The conciseness of the functional paradigm — less is more
2. The predictability of pure function and consistent behavior
3. The readability of declarative immutability and clear data flow
4. The performance of imperative JavaScript when it counts

Write concise, declarative code with no side effects — without sacrificing performance or maintainability

Natively, JavaScript includes functional patterns through built-in array methods like .map, .filter, and .reduce, which makes it easy to compose logic through chaining. However, JavaScript is considered as a multi-paradigm scripting language — not a purely functional one like Haskell. It is not optimized for the functional paradigm, especially heavy functional chaining. As the codebase grows in size and complexity, performance and maintainability often suffer.

With mauss, you can write shorter, simpler, more declarative code without the overhead of deep chaining or over-abstractions. It encourages clarity and composition while staying close to JavaScript's performance model. Of course, no utility library replaces good design. mauss doesn't prevent bad practices — but it nudges you toward better ones.

Usage

mauss is modular, tree-shakeable, and comes with no dependencies — its footprint is minimal, basically free. It also includes some convenience exports to streamline your workflow, such as:

/prettier.config.js

An opinionated Prettier config for consistent code style with zero setup. Just point to it in your package.json:

{
    "prettier": "mauss/prettier.config.js"
}

This config includes:

• Ignore rules for pnpm-lock.yaml and generated directories like .svelte-kit/
• Support for *.svelte files via prettier-plugin-svelte (install separately)
• Optional sorting for package.json via prettier-plugin-sort-package-json (install separately)

/tsconfig.json

A minimal base tsconfig with strict type-checking and sensible defaults for consistent project environments. Designed to reduce boilerplate and encourage best practices. Just extend it in your tsconfig.json:

{
    "extends": "mauss/tsconfig.json"
}