JSFiddle - React, Tailwind, and code Playground
HTML
<span>Span</span>
<svg width="620" height="100">
<text id="r123" x="30" y="90" fill="#ED6E46" font-size="100" font-family="'Leckerli One', cursive">Text</text>
</svg>
JavaScript
var text = document.getElementsByTagName('text')[0];
var span = document.getElementsByTagName('span')[0];
console.log('text length1: ' + text.getComputedTextLength());
text.textContent = 'NewText'
span.innerHTML = 'NewText'
console.log('text: ' + text.innerHTML);
console.log('span: ' + span.innerHTML);
console.log('text length2: ' + text.getComputedTextLength());