lino-arguments

A unified configuration library combining environment variables and CLI arguments with a clear priority chain.

Available in both JavaScript and Rust.

Overview

lino-arguments provides a unified configuration system that automatically loads configuration from multiple sources with a clear priority chain:

1. CLI arguments - Highest priority (manually entered options)
2. Environment variables - With case-insensitive lookup
3. Configuration file - Dynamic config file path via CLI
4. Default values - Fallback values

Languages

JavaScript

The JavaScript version supports Node.js, Bun, and Deno runtimes.

npm install lino-arguments

import { makeConfig } from 'lino-arguments';

const config = makeConfig({
  yargs: ({ yargs, getenv }) =>
    yargs.option('port', { default: getenv('PORT', 3000) }),
});

See js/README.md for full documentation.

Rust

The Rust version uses clap for argument parsing.

[dependencies]
lino-arguments = "0.2"

use clap::Parser;
use lino_arguments::{getenv_int, getenv_bool};

#[derive(Parser)]
struct Args {
    #[arg(short, long, default_value_t = getenv_int("PORT", 3000) as u16)]
    port: u16,
}

See rust/README.md for full documentation.

Repository Structure

lino-arguments/
├── js/                    # JavaScript implementation
│   ├── src/              # Source code
│   ├── tests/            # Tests
│   ├── examples/         # Usage examples
│   ├── .changeset/       # Changesets for JS releases
│   └── package.json      # npm package config
├── rust/                  # Rust implementation
│   ├── src/              # Source code
│   ├── tests/            # Integration tests
│   ├── changelog.d/      # Changelog fragments for Rust releases
│   └── Cargo.toml        # Cargo package config
├── scripts/              # Shared release/CI scripts
├── .github/workflows/    # CI/CD workflows
│   ├── js.yml           # JavaScript CI/CD
│   └── rust.yml         # Rust CI/CD
└── docs/                 # Documentation

Development

JavaScript

cd js
npm install
npm test
npm run lint

Rust

cd rust
cargo test
cargo clippy
cargo fmt

Contributing

See the language-specific directories for contribution guidelines:

• JavaScript
• Rust

Both languages use changelog fragments for versioning:

• JavaScript uses .changeset/ with changesets
• Rust uses changelog.d/ with markdown fragments

License

This is free and unencumbered software released into the public domain. See the LICENSE file for details.