Rocket.Chat/packages/rocketchat-lib/lib/getUserPreference.js

/**
 * Tries to retrieve the user preference falling back to a default system
 * value or to a default value if it is passed as argument
*/
RocketChat.getUserPreference = function(user, key, defaultValue = undefined) {
	let preference;
	if (typeof user === typeof '') {
		user = RocketChat.models.Users.findOne(user, { fields: { [`settings.preferences.${ key }`]: 1 } });
	}
	if (user && user.settings && user.settings.preferences &&
		user.settings.preferences.hasOwnProperty(key)) {
		preference = user.settings.preferences[key];
	} else if (defaultValue === undefined) {
		preference = RocketChat.settings.get(`Accounts_Default_User_Preferences_${ key }`);
	}

	return preference !== undefined ? preference : defaultValue;
};