is-path-inside 
Check if a path is inside another path
Install
$ npm install is-path-inside
Usage
const isPathInside = require('is-path-inside');
isPathInside('a/b/c', 'a/b');
//=> true
isPathInside('a/b/c', 'x/y');
//=> false
isPathInside('a/b/c', 'a/b/c');
//=> false
isPathInside('/Users/sindresorhus/dev/unicorn', '/Users/sindresorhus');
//=> true
License
MIT © Sindre Sorhus