intellij idea - How to tell to JetBrains IDE that this javascript variable changed type to another?

Question

Web API has Element interface which extends Node interface. How to tell JetBrains IDE that this particular Node is Element?

Hope the code below explains everything.

/**
* @param {Node} node 
* @return {string}
*/
function extractor(node) {
   let text;
   if (node.nodeType === Node.ELEMENT_NODE) {
       // On the next line IDE shows a warning,
       // that innerHTML property is not defined for Node.
       // How to tell IDE that node variable became and Element here?
       text = node.innerHTML;
   } else {
       text = node.textContent;
   }
   return text;
}

I'm using PyCharm Professional, but I don't think it matters.

question from:https://stackoverflow.com/questions/66058986/how-to-tell-to-jetbrains-ide-that-this-javascript-variable-changed-type-to-anoth

Answer 1

You can't.

If you do want, you can use Typescript instead.

text = (node as Element).innerHTML;

But in javascript, there is no strict types, you can only try:

/**
* @param {Node | Element} node 
* @return {string}
*/