ES6 module bundler for JavaScript

 Rollup is a module bundler for JavaScript which compiles small pieces of code
 into something larger and more complex, such as a library or application. It
 uses the standardized ES module format for code, instead of previous
 idiosyncratic solutions such as CommonJS and AMD.
 .
 ES modules let you freely and seamlessly combine the most useful individual
 functions from your favorite libraries. Rollup can optimize ES modules for
 faster native loading in modern browsers, or output a legacy module format
 allowing ES module workflows today.
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 node-chokidar is required to use the --watch option