getElementsByClassName returns wrong results when given multiple classes

[hombrew]

To Reproduce

import { Window } from "happy-dom";

const window = new Window();
const document = window.document;

document.body.innerHTML = `
<div class="class1 class2">
  <div class="class2">
    <span>hi</span>
  </div>
</div>`;

const arr1 = Array.from(document.getElementsByClassName("class1 class2"));
console.log(arr1.length); // output: 0 - wrong

Expected behavior
in this case getElementsByClassName should return 1 element as shown here

Device:

• OS: OSX Sonoma 14.6.1
• Browser Chrome
• Version 129.0.6668.58

Additional context
based on the same code, comma separated classes work as expected:

const arr2 = Array.from(document.getElementsByClassName("class1, class2"));
console.log(arr2.length); // output: 1 - ok

[capricorn86]

Thank you for reporting @hombrew! 🙂

Big thanks to @kylehalleman for contributing with a fix ⭐

The fix has been released in v16.1.0.