dispatch keyed values to keyed functions

branchDispatch.js

const branchDispatch = (obj, table, defaultFn) =>
  Object.entries(obj)
    .map(([key, value]) =>
      table[key] != null
        ? [key, table[key](value)]
        : typeof defaultFn === 'function'
          ? [key, defaultFn(value)]
          : [key, undefined]
    )
    .reduce((results, [key, value]) => {
      results[key] = value
      return results
    }, {})