Function updateDom

mini-react/src/mini-react.js:117–153

(dom, prevProps, nextProps)

    const isGone = (prev, next) => key => !(key in next)
    
    function updateDom(dom, prevProps, nextProps) {
      //Remove old or changed event listeners
      Object.keys(prevProps)
        .filter(isEvent)
        .filter(
          key => !(key in nextProps) || isNew(prevProps, nextProps)(key)
        )
        .forEach(name => {
          const eventType = name.toLowerCase().substring(2)
          dom.removeEventListener(eventType, prevProps[name])
        })
    
      // Remove old properties
      Object.keys(prevProps)
        .filter(isProperty)
        .filter(isGone(prevProps, nextProps))
        .forEach(name => {
          dom[name] = ""
        })
    
      // Set new or changed properties
      Object.keys(nextProps)
        .filter(isProperty)
        .filter(isNew(prevProps, nextProps))
        .forEach(name => {
          dom[name] = nextProps[name]
        })
    
      // Add event listeners
      Object.keys(nextProps)
        .filter(isEvent)
        .filter(isNew(prevProps, nextProps))
        .forEach(name => {
          const eventType = name.toLowerCase().substring(2)
          dom.addEventListener(eventType, nextProps[name])
        })
    }
      
    
    function reconcileChildren(wipFiber, elements) {