Function isSourceEqual

lib/util/source.js:39–63

(a, b)

 * @returns {boolean} true, when both sources are equal
 */
const isSourceEqual = (a, b) => {
	if (a === b) return true;
	const cache1 = equalityCache.get(a);
	if (cache1 !== undefined) {
		const result = cache1.get(b);
		if (result !== undefined) return result;
	}
	const result = _isSourceEqual(a, b);
	if (cache1 !== undefined) {
		cache1.set(b, result);
	} else {
		const map = new WeakMap();
		map.set(b, result);
		equalityCache.set(a, map);
	}
	const cache2 = equalityCache.get(b);
	if (cache2 !== undefined) {
		cache2.set(a, result);
	} else {
		const map = new WeakMap();
		map.set(a, result);
		equalityCache.set(b, map);
	}
	return result;
};

// TODO remove in webpack 6, this is protection against authors who directly use `webpack-sources` outdated version
/**