Check if a project is using Yarn

Useful for tools that needs to know whether to use yarn or npm to install dependencies.

It checks if a yarn.lock file is present in the working directory.

$ npm install has-yarn

.
├── foo
│   └── package.json
└── bar
    ├── package.json
    └── yarn.lock

import hasYarn from 'has-yarn';

hasYarn('foo');
//=> false

hasYarn('bar');
//=> true

Returns a boolean of whether the project uses Yarn.

Type: string
Default: process.cwd()

The current working directory.

• has-yarn-cli - CLI for this module