Property 'tagName' does not exist on type ChildNode [Typescript]

Question

I am looping over childNodes from a parent node. I want to access the tagName of the child nodes, but error is tagName doesn't exist on type ChildNode.

const contentParsed = new DOMParser().parseFromString(content, 'text/xml');
const svgBody = contentParsed.querySelector('svg');

if (svgBody === null) throw new Error('content must be svg');
svgBody.childNodes.forEach((node) => node.tagName) // Property 'tagName' does not exist on type 'ChildNode'.ts(2339)

It works with javascript

const svgStr = `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32"><title></title><path d="M 2.6846088,10.906645 H 28.979394 v 8.389403 H 15.580319 l -0.719092,1.438183 -3.811186,0.143819 -0.575273,-1.582002 H 2.6846088 Z" fill="#fff"/><path d="M2,10.555H30v9.335H16v1.556H9.778V19.889H2Zm1.556,7.779H6.667V13.666H8.222v4.667H9.778V12.111H3.556Zm7.778-6.223v7.779h3.111V18.334h3.111V12.111Zm3.111,1.556H16v3.112H14.444Zm4.667-1.556v6.223h3.111V13.666h1.556v4.667h1.556V13.666h1.556v4.667h1.556V12.111Z" fill="#cb3837"/></svg>`
const contentParsed = new DOMParser().parseFromString(svgStr, 'text/xml');
const svgBody = contentParsed.querySelector('svg');

if (svgBody === null) throw new Error('content must be svg');
svgBody.childNodes.forEach(node => console.log(node.tagName))

Answer 1

childNodes can contain non-element nodes, use children instead.

It works in JavaScript because JS isn't type safe and your parent node happened to only have elements as children (or it printed undefined).