app-root-dir

In practice, app-root-dir does exactly what it promises with a trivial API: call `get()` and you get the root directory. It works by traversing up from the current directory to find a package.json, which handles most cases correctly. The entire API surface is literally one function, so there's nothing to learn.

However, the package hasn't been updated since 2015, which shows in several ways. There are no TypeScript definitions (even in DefinitelyTyped), so you lose all type safety and autocompletion. The error handling is minimal - if it can't find a package.json, behavior is unpredictable. In monorepos or workspaces, it may not identify the root you expect since it stops at the first package.json.

For simple Node.js apps with a single package.json at the root, it works fine. But modern tooling like `__dirname` with ES modules, `import.meta.url`, or even `process.cwd()` often handles this better with zero dependencies. The maintenance status is concerning for long-term projects.

This package does exactly one thing: returns the application root directory by traversing up from require.main.filename until it finds package.json. The API is trivial - just require it and call .get(). No configuration, no options, no logging hooks. It works reliably in straightforward scenarios and has zero dependencies, which is nice from a security standpoint.

The main concern is it hasn't been updated since 2015. It doesn't handle edge cases well - no error handling if package.json is missing, undefined behavior with ES modules, and can return unexpected results in monorepos or when using build tools that modify require.main. There's no timeout protection (though the sync operation is fast), no observability, and the hardcoded assumptions about project structure don't align with modern tooling.

For simple Express apps or traditional Node projects with a single package.json at the root, it does the job without fuss. But for anything complex, you'll want something more robust or just use process.cwd() with proper configuration management.

This package does exactly one thing: exports a `get()` function that returns the application root directory as a string. The API is trivial - just `require('app-root-dir').get()` - which makes it immediately understandable. It works by walking up from `require.main.filename` until it finds a directory with package.json, which handles most common cases correctly.

The main concern is the package hasn't been updated since 2015 and lacks TypeScript definitions in DefinitelyTyped. You'll need to add your own declaration file (`declare module 'app-root-dir' { export function get(): string; }`) for any TypeScript project. There's minimal documentation - just a brief README - but honestly the API is so simple it doesn't need much. Error handling is basically non-existent; if it can't find a package.json, behavior is undefined.

For modern projects, I'd recommend using `__dirname` with proper bundler configuration, or newer alternatives that are actively maintained. This package works fine for legacy Node.js apps where you need a quick solution, but the lack of maintenance and TypeScript support makes it hard to recommend for new projects in 2024.