/** * Module exports. */ module.exports = deprecate; /** * Mark that a method should not be used. * Returns a modified function which warns once by default. * * If `localStorage.noDeprecation = true` is set, then it is a no-op. * * If `localStorage.throwDeprecation = true` is set, then deprecated functions * will throw an Error when invoked. * * If `localStorage.traceDeprecation = true` is set, then deprecated functions * will invoke `console.trace()` instead of `console.error()`. * * @param {Function} fn - the function to deprecate * @param {String} msg - the string to print to the console when `fn` is invoked * @returns {Function} a new "deprecated" version of `fn` * @api public */ function deprecate (fn, msg) { if (config('noDeprecation')) { return fn; } var warned = false; function deprecated() { if (!warned) { if (config('throwDeprecation')) { throw new Error(msg); } else if (config('traceDeprecation')) { console.trace(msg); } else { console.warn(msg); } warned = true; } return fn.apply(this, arguments); } return deprecated; } /** * Checks `localStorage` for boolean values for the given `name`. * * @param {String} name * @returns {Boolean} * @api private */ function config (name) { // accessing global.localStorage can trigger a DOMException in sandboxed iframes try { if (!global.localStorage) return false; } catch (_) { return false; } var val = global.localStorage[name]; if (null == val) return false; return String(val).toLowerCase() === 'true'; }