Function spyOnElementAttributes

test/_util/helpers.jsx:264–284

()

let attributesSpy, originalAttributesPropDescriptor;

export function spyOnElementAttributes() {
	const test = Object.getOwnPropertyDescriptor(Element.prototype, 'attributes');

	// IE11 doesn't correctly restore the prototype methods so we have to check
	// whether this prototype method is already a sinon spy.
	if (!attributesSpy && !(test && test.get && test.get.isSinonProxy)) {
		if (!originalAttributesPropDescriptor) {
			originalAttributesPropDescriptor = Object.getOwnPropertyDescriptor(
				Element.prototype,
				'attributes'
			);
		}

		attributesSpy = sinon.spy(Element.prototype, 'attributes', ['get']);
	} else if (test && test.get && test.get.isSinonProxy) {
		// Due to IE11 not resetting we will do this manually when it is a proxy.
		test.get.resetHistory();
	}

	return attributesSpy || test;
}

function restoreElementAttributes() {
	if (originalAttributesPropDescriptor) {