/*
Copyright (c) 2014, Yahoo! Inc. All rights reserved.
Copyrights licensed under the New BSD License.
See the accompanying LICENSE file for terms.
*/
'use strict';
var randomBytes = require('randombytes');
// Generate an internal UID to make the regexp pattern harder to guess.
var UID_LENGTH = 16;
var UID = generateUID();
var PLACE_HOLDER_REGEXP = new RegExp('(\\\\)?"@__(F|R|D|M|S|A|U|I|B|L)-' + UID + '-(\\d+)__@"', 'g');
var IS_NATIVE_CODE_REGEXP = /\{\s*\[native code\]\s*\}/g;
var IS_PURE_FUNCTION = /function.*?\(/;
var IS_ARROW_FUNCTION = /.*?=>.*?/;
var UNSAFE_CHARS_REGEXP = /[<>\/\u2028\u2029]/g;
var RESERVED_SYMBOLS = ['*', 'async'];
// Mapping of unsafe HTML and invalid JavaScript line terminator chars to their
// Unicode char counterparts which are safe to use in JavaScript strings.
var ESCAPED_CHARS = {
'<' : '\\u003C',
'>' : '\\u003E',
'/' : '\\u002F',
'\u2028': '\\u2028',
'\u2029': '\\u2029'
};
function escapeUnsafeChars(unsafeChar) {
return ESCAPED_CHARS[unsafeChar];
}
function generateUID() {
var bytes = randomBytes(UID_LENGTH);
var result = '';
for(var i=0; i<UID_LENGTH; ++i) {
result += bytes[i].toString(16);
}
return result;
}
function deleteFunctions(obj){
var functionKeys = [];
for (var key in obj) {
if (typeof obj[key] === "function") {
functionKeys.push(key);
}
}
for (var i = 0; i < functionKeys.length; i++) {
delete obj[functionKeys[i]];
}
}
module.exports = function serialize(obj, options) {
options || (options = {});
// Backwards-compatibility for `space` as the second argument.
if (typeof options === 'number' || typeof options === 'string') {
options = {space: options};
}
var functions = [];
var regexps = [];
var dates = [];
var maps = [];
var sets = [];
var arrays = [];
var undefs = [];
var infinities= [];
var bigInts = [];
var urls = [];
// Returns placeholders for functions and regexps (identified by index)
// which are later replaced by their string representation.
function replacer(key, value) {
// For nested function
if(options.ignoreFunction){
deleteFunctions(value);
}
if (!value && value !== undefined) {
return value;
}
// If the value is an object w/ a toJSON method, toJSON is called before
// the replacer runs, so we use this[key] to get the non-toJSONed value.
var origValue = this[key];
var type = typeof origValue;
if (type === 'object') {
if(origValue instanceof RegExp) {
return '@__R-' + UID + '-' + (regexps.push(origValue) - 1) + '__@';
}
if(origValue instanceof Date) {
return '@__D-' + UID + '-' + (dates.push(origValue) - 1) + '__@';
}
if(origValue instanceof Map) {
return '@__M-' + UID + '-' + (maps.push(origValue) - 1) + '__@';
}
if(origValue instanceof Set) {
return '@__S-' + UID + '-' + (sets.push(origValue) - 1) + '__@';
}
if(origValue instanceof Array) {
var isSparse = origValue.filter(function(){return true}).length !== origValue.length;
if (isSparse) {
return '@__A-' + UID + '-' + (arrays.push(origValue) - 1) + '__@';
}
}
if(origValue instanceof URL) {
return '@__L-' + UID + '-' + (urls.push(origValue) - 1) + '__@';
}
}
if (type === 'function') {
return '@__F-' + UID + '-' + (functions.push(origValue) - 1) + '__@';
}
if (type === 'undefined') {
return '@__U-' + UID + '-' + (undefs.push(origValue) - 1) + '__@';
}
if (type === 'number' && !isNaN(origValue) && !isFinite(origValue)) {
return '@__I-' + UID + '-' + (infinities.push(origValue) - 1) + '__@';
}
if (type === 'bigint') {
return '@__B-' + UID + '-' + (bigInts.push(origValue) - 1) + '__@';
}
return value;
}
function serializeFunc(fn) {
var serializedFn = fn.toString();
if (IS_NATIVE_CODE_REGEXP.test(serializedFn)) {
throw new TypeError('Serializing native function: ' + fn.name);
}
// pure functions, example: {key: function() {}}
if(IS_PURE_FUNCTION.test(serializedFn)) {
return serializedFn;
}
// arrow functions, example: arg1 => arg1+5
if(IS_ARROW_FUNCTION.test(serializedFn)) {
return serializedFn;
}
var argsStartsAt = serializedFn.indexOf('(');
var def = serializedFn.substr(0, argsStartsAt)
.trim()
.split(' ')
.filter(function(val) { return val.length > 0 });
var nonReservedSymbols = def.filter(function(val) {
return RESERVED_SYMBOLS.indexOf(val) === -1
});
// enhanced literal objects, example: {key() {}}
if(nonReservedSymbols.length > 0) {
return (def.indexOf('async') > -1 ? 'async ' : '') + 'function'
+ (def.join('').indexOf('*') > -1 ? '*' : '')
+ serializedFn.substr(argsStartsAt);
}
// arrow functions
return serializedFn;
}
// Check if the parameter is function
if (options.ignoreFunction && typeof obj === "function") {
obj = undefined;
}
// Protects against `JSON.stringify()` returning `undefined`, by serializing
// to the literal string: "undefined".
if (obj === undefined) {
return String(obj);
}
var str;
// Creates a JSON string representation of the value.
// NOTE: Node 0.12 goes into slow mode with extra JSON.stringify() args.
if (options.isJSON && !options.space) {
str = JSON.stringify(obj);
} else {
str = JSON.stringify(obj, options.isJSON ? null : replacer, options.space);
}
// Protects against `JSON.stringify()` returning `undefined`, by serializing
// to the literal string: "undefined".
if (typeof str !== 'string') {
return String(str);
}
// Replace unsafe HTML and invalid JavaScript line terminator chars with
// their safe Unicode char counterpart. This _must_ happen before the
// regexps and functions are serialized and added back to the string.
if (options.unsafe !== true) {
str = str.replace(UNSAFE_CHARS_REGEXP, escapeUnsafeChars);
}
if (functions.length === 0 && regexps.length === 0 && dates.length === 0 && maps.length === 0 && sets.length === 0 && arrays.length === 0 && undefs.length === 0 && infinities.length === 0 && bigInts.length === 0 && urls.length === 0) {
return str;
}
// Replaces all occurrences of function, regexp, date, map and set placeholders in the
// JSON string with their string representations. If the original value can
// not be found, then `undefined` is used.
return str.replace(PLACE_HOLDER_REGEXP, function (match, backSlash, type, valueIndex) {
// The placeholder may not be preceded by a backslash. This is to prevent
// replacing things like `"a\"@__R-<UID>-0__@"` and thus outputting
// invalid JS.
if (backSlash) {
return match;
}
if (type === 'D') {
return "new Date(\"" + dates[valueIndex].toISOString() + "\")";
}
if (type === 'R') {
return "new RegExp(" + serialize(regexps[valueIndex].source) + ", \"" + regexps[valueIndex].flags + "\")";
}
if (type === 'M') {
return "new Map(" + serialize(Array.from(maps[valueIndex].entries()), options) + ")";
}
if (type === 'S') {
return "new Set(" + serialize(Array.from(sets[valueIndex].values()), options) + ")";
}
if (type === 'A') {
return "Array.prototype.slice.call(" + serialize(Object.assign({ length: arrays[valueIndex].length }, arrays[valueIndex]), options) + ")";
}
if (type === 'U') {
return 'undefined'
}
if (type === 'I') {
return infinities[valueIndex];
}
if (type === 'B') {
return "BigInt(\"" + bigInts[valueIndex] + "\")";
}
if (type === 'L') {
return "new URL(\"" + urls[valueIndex].toString() + "\")";
}
var fn = functions[valueIndex];
return serializeFunc(fn);
});
}