$ npm install pkg-dir

/
└── Users
    └── sindresorhus
        └── foo
            ├── package.json
            └── bar
                ├── baz
                └── example.js

js
// example.js
const pkgDir = require('pkg-dir');

(async () => {
	const rootDir = await pkgDir(__dirname);

	console.log(rootDir);
	//=> '/Users/sindresorhus/foo'
})();

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