const booleanAttributes = [ 'allowfullscreen' , 'async' , 'autofocus' , 'autoplay' , 'checked' , 'compact' , 'controls' , 'declare' , 'default' , 'defaultchecked' , 'defaultmuted' , 'defaultselected' , 'defer' , 'disabled' , 'draggable' , 'enabled' , 'formnovalidate' , 'hidden' , 'indeterminate' , 'inert' , 'ismap' , 'itemscope' , 'loop' , 'multiple' , 'muted' , 'nohref' , 'noresize' , 'noshade' , 'novalidate' , 'nowrap' , 'open' , 'pauseonexit' , 'readonly' , 'required' , 'reversed' , 'scoped' , 'seamless' , 'selected' , 'sortable' , 'spellcheck' , 'translate' , 'truespeed' , 'typemustmatch' , 'visible' , ] ; const booleanAttributeDictionary = Object . create ( null ) ; for ( let i = 0 , count = booleanAttributes . length ; i < count ; i ++ ) booleanAttributeDictionary [ booleanAttributes [ i ] ] = true ; export function isBooleanAttribute ( key ) { return booleanAttributeDictionary [ key ] === true ; }