es6 code not supported in some browsers

[hoperyy]

Can you support es5.

Some library like ''string-width" depends on it so I cannot modifiy the es6 code directly.

Thanks!

[sindresorhus]

This module mainly targets Node.js, not the browser. It's up to you to transpile it with Babel if you want to use it in the browser. You can find a more detailed explanation here: sindresorhus/ama#446

If you use Webpack, check out babel-engine-plugin, which transpiles only the dependencies that needs to be transpiled.