@wordpress/data/src/plugins/persistence/storage/default.js

Data module for WordPress.

/**
 * Internal dependencies
 */
import objectStorage from './object';

let storage;

try {
	// Private Browsing in Safari 10 and earlier will throw an error when
	// attempting to set into localStorage. The test here is intentional in
	// causing a thrown error as condition for using fallback object storage.
	storage = window.localStorage;
	storage.setItem( '__wpDataTestLocalStorage', '' );
	storage.removeItem( '__wpDataTestLocalStorage' );
} catch ( error ) {
	storage = objectStorage;
}

export default storage;