panoply

module Jekyll
  module Filters
    def summarize(str, splitstr = /\s*<div id="extended">/)
      str.split(splitstr)[0]
    end
  end
end

panoply

λ yarn run start
yarn run v1.12.3
$ rollup -c -w --environment DEV
rollup v1.1.0
bundles ./src/index.js → public\app.js...
[!] (commonjs plugin) SyntaxError: Unexpected token (2821:19) in C:\.dev\js\.react\dota\node_modules\react-dom\cjs\react-dom.development.js
node_modules\react-dom\cjs\react-dom.development.js (2821:19)
2819: // on the client side because the browsers are inconsistent. Instead we call focus().
2820: 'autoFocus', 'autoPlay', 'controls', 'default', 'defer', 'disabled', 'formNoValidate', 'hidden', 'loop', 'noModule', 'noValidate', 'open', 'playsInline', 'readOnly', 'required', 'reversed', 'scoped', 'seamless',
2821: // Microdata