const yarnGlobal = require('yarn-global')

yarnGlobal.getDirectory()
//=> /Users/name/.config/yarn/global/node_modules

yarnGlobal.inDirectory(process.cwd())
// Check if a path is a child path of the value of `yarnGlobal.getDirectory()`

yarnGlobal.getDependencies()
// An array of denpendencies installed by `yarn global add`

yarnGlobal.hasDependency('create-react-app')
// Check if you have installed it via `yarn global add`
//=> true

yarnGlobal.hasPackage('minimist')
// Check if `/Users/name/.config/yarn/global/node_modules/minimist` exists
// you may not have installed it by `yarn global add`
//=> true