withHead hyperapp HOA

withHead.js

 const withHead = (() => {
      let _setHead = null
      let setHead = nodes => {
          if (_setHead) return _setHead(nodes)
          app({
              init: nodes,
              view: nodes => nodes,
              node: document.head,
              middleware: d => (_setHead = d),
          })
      }

      return app => defs => {
          app({
              ...defs,
              middleware: dispatch => (action, payload) => {
                  if (
                      typeof action !== 'function' &&
                      !Array.isArray(action)
                  ) {
                      setHead(defs.head(action))
                  }
                  return dispatch(action, payload)
              },
          })
      }
  })()