axe-core/lib/checks/media/caption.js

Accessibility engine for automated Web UI testing

var tracks = axe.utils.querySelectorAll(virtualNode, 'track');

if (tracks.length) {
	// return false if any track has kind === 'caption'
	return !tracks.some(({ actualNode }) => (
		(actualNode.getAttribute('kind') || '').toLowerCase() === 'captions'
	));
}
// Undefined if there are no tracks - media may be decorative
return undefined;