What a QUnit page looks like from the outside.

The markup every QUnit runner has had since 1.x: the fixture element its docs tell you to add, the reporter's own container, or a script that is QUnit itself. Checked against the HTML rather than against the URL, because /test, /test/, /tests/index.html and /qunit.html are all the same page and none of them is a naming convention.

import { looksLikeQUnitPage } from './remote-page.ts';

looksLikeQUnitPage('<div id="qunit-fixture"></div>'); // true
looksLikeQUnitPage('<script src="https://code.jquery.com/qunit/qunit-2.17.2.js"></script>'); // true
looksLikeQUnitPage('<a href="a-test.js">a-test.js</a>'); // false — a directory listing