Function spy

test/browser/refs.test.jsx:9–13

(name, ...args)

// gives call count and argument errors names (otherwise sinon just uses "spy"):
let spy = (name, ...args) => {
	let spy = sinon.spy(...args);
	spy.displayName = `spy('${name}')`;
	return spy;
};

describe('refs', () => {
	let scratch;