json.js

// Copyright 2009 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// Date toJSON
assertEquals("1970-01-01T00:00:00.000Z", new Date(0).toJSON());
assertEquals("1979-01-11T08:00:00.000Z", new Date("1979-01-11 08:00 GMT").toJSON());
assertEquals("2005-05-05T05:05:05.000Z", new Date("2005-05-05 05:05:05 GMT").toJSON());
var n1 = new Date(10000);
n1.toISOString = function () { return "foo"; };
assertEquals("foo", n1.toJSON());
var n2 = new Date(10001);
n2.toISOString = null;
assertThrows(function () { n2.toJSON(); }, TypeError);
var n4 = new Date(10003);
n4.toISOString = function () {
  assertEquals(0, arguments.length);
  assertEquals(this, n4);
  return null;
};
assertEquals(null, n4.toJSON());

assertTrue(Object.prototype === JSON.__proto__);
assertEquals("[object JSON]", Object.prototype.toString.call(JSON));

//Test Date.prototype.toJSON as generic function.
var d1 = {toJSON: Date.prototype.toJSON,
         toISOString: function() { return 42; }};
assertEquals(42, d1.toJSON());

var d2 = {toJSON: Date.prototype.toJSON,
          valueOf: function() { return Infinity; },
          toISOString: function() { return 42; }};
assertEquals(null, d2.toJSON());

var d3 = {toJSON: Date.prototype.toJSON,
          valueOf: "not callable",
          toString: function() { return Infinity; },
          toISOString: function() { return 42; }};

assertEquals(null, d3.toJSON());

var d4 = {toJSON: Date.prototype.toJSON,
          valueOf: "not callable",
          toString: "not callable either",
          toISOString: function() { return 42; }};
assertThrows("d4.toJSON()", TypeError);  // ToPrimitive throws.

var d5 = {toJSON: Date.prototype.toJSON,
          valueOf: "not callable",
          toString: function() { return "Infinity"; },
          toISOString: function() { return 42; }};
assertEquals(42, d5.toJSON());

var d6 = {toJSON: Date.prototype.toJSON,
          toISOString: function() { return ["not primitive"]; }};
assertEquals(["not primitive"], d6.toJSON());

var d7 = {toJSON: Date.prototype.toJSON,
          ISOString: "not callable"};
assertThrows("d7.toJSON()", TypeError);

// DontEnum
for (var p in this) {
  assertFalse(p == "JSON");
}

// Parse
assertEquals({}, JSON.parse("{}"));
assertEquals({42:37}, JSON.parse('{"42":37}'));
assertEquals(null, JSON.parse("null"));
assertEquals(true, JSON.parse("true"));
assertEquals(false, JSON.parse("false"));
assertEquals("foo", JSON.parse('"foo"'));
assertEquals("f\no", JSON.parse('"f\\no"'));
assertEquals("\b\f\n\r\t\"\u2028\/\\",
             JSON.parse('"\\b\\f\\n\\r\\t\\"\\u2028\\/\\\\"'));
assertEquals([1.1], JSON.parse("[1.1]"));
assertEquals([1], JSON.parse("[1.0]"));

assertEquals(0, JSON.parse("0"));
assertEquals(1, JSON.parse("1"));
assertEquals(0.1, JSON.parse("0.1"));
assertEquals(1.1, JSON.parse("1.1"));
assertEquals(1.1, JSON.parse("1.100000"));
assertEquals(1.111111, JSON.parse("1.111111"));
assertEquals(-0, JSON.parse("-0"));
assertEquals(-1, JSON.parse("-1"));
assertEquals(-0.1, JSON.parse("-0.1"));
assertEquals(-1.1, JSON.parse("-1.1"));
assertEquals(-1.1, JSON.parse("-1.100000"));
assertEquals(-1.111111, JSON.parse("-1.111111"));
assertEquals(11, JSON.parse("1.1e1"));
assertEquals(11, JSON.parse("1.1e+1"));
assertEquals(0.11, JSON.parse("1.1e-1"));
assertEquals(11, JSON.parse("1.1E1"));
assertEquals(11, JSON.parse("1.1E+1"));
assertEquals(0.11, JSON.parse("1.1E-1"));

assertEquals([], JSON.parse("[]"));
assertEquals([1], JSON.parse("[1]"));
assertEquals([1, "2", true, null], JSON.parse('[1, "2", true, null]'));

assertEquals("", JSON.parse('""'));
assertEquals(["", "", -0, ""], JSON.parse('[    ""  ,    ""  ,   -0,    ""]'));
assertEquals("", JSON.parse('""'));


function GetFilter(name) {
  function Filter(key, value) {
    return (key == name) ? undefined : value;
  }
  return Filter;
}

var pointJson = '{"x": 1, "y": 2}';
assertEquals({'x': 1, 'y': 2}, JSON.parse(pointJson));
assertEquals({'x': 1}, JSON.parse(pointJson, GetFilter('y')));
assertEquals({'y': 2}, JSON.parse(pointJson, GetFilter('x')));

assertEquals([1, 2, 3], JSON.parse("[1, 2, 3]"));

var array1 = JSON.parse("[1, 2, 3]", GetFilter(1));
assertEquals([1, , 3], array1);
assertFalse(array1.hasOwnProperty(1));  // assertEquals above is not enough

var array2 = JSON.parse("[1, 2, 3]", GetFilter(2));
assertEquals([1, 2, ,], array2);
assertFalse(array2.hasOwnProperty(2));

function DoubleNumbers(key, value) {
  return (typeof value == 'number') ? 2 * value : value;
}

var deepObject = '{"a": {"b": 1, "c": 2}, "d": {"e": {"f": 3}}}';
assertEquals({"a": {"b": 1, "c": 2}, "d": {"e": {"f": 3}}},
             JSON.parse(deepObject));
assertEquals({"a": {"b": 2, "c": 4}, "d": {"e": {"f": 6}}},
             JSON.parse(deepObject, DoubleNumbers));

function TestInvalid(str) {
  assertThrows(function () { JSON.parse(str); }, SyntaxError);
}

TestInvalid('abcdef');
TestInvalid('isNaN()');
TestInvalid('{"x": [1, 2, deepObject]}');
TestInvalid('[1, [2, [deepObject], 3], 4]');
TestInvalid('function () { return 0; }');

TestInvalid("[1, 2");
TestInvalid('{"x": 3');

// JavaScript number literals not valid in JSON.
TestInvalid('[01]');
TestInvalid('[.1]');
TestInvalid('[1.]');
TestInvalid('[1.e1]');
TestInvalid('[-.1]');
TestInvalid('[-1.]');

// Plain invalid number literals.
TestInvalid('-');
TestInvalid('--1');
TestInvalid('-1e');
TestInvalid('1e--1]');
TestInvalid('1e+-1');
TestInvalid('1e-+1');
TestInvalid('1e++1');

// JavaScript string literals not valid in JSON.
TestInvalid("'single quote'");  // Valid JavaScript
TestInvalid('"\\a invalid escape"');
TestInvalid('"\\v invalid escape"');  // Valid JavaScript
TestInvalid('"\\\' invalid escape"');  // Valid JavaScript
TestInvalid('"\\x42 invalid escape"');  // Valid JavaScript
TestInvalid('"\\u202 invalid escape"');
TestInvalid('"\\012 invalid escape"');
TestInvalid('"Unterminated string');
TestInvalid('"Unterminated string\\"');
TestInvalid('"Unterminated string\\\\\\"');

// Test bad JSON that would be good JavaScript (ES5).
TestInvalid("{true:42}");
TestInvalid("{false:42}");
TestInvalid("{null:42}");
TestInvalid("{'foo':42}");
TestInvalid("{42:42}");
TestInvalid("{0:42}");
TestInvalid("{-1:42}");

// Test for trailing garbage detection.
TestInvalid('42 px');
TestInvalid('42 .2');
TestInvalid('42 2');
TestInvalid('42 e1');
TestInvalid('"42" ""');
TestInvalid('"42" ""');
TestInvalid('"" ""');
TestInvalid('true ""');
TestInvalid('false ""');
TestInvalid('null ""');
TestInvalid('null ""');
TestInvalid('[] ""');
TestInvalid('[true] ""');
TestInvalid('{} ""');
TestInvalid('{"x":true} ""');
TestInvalid('"Garbage""After string"');

// Stringify

function TestStringify(expected, input) {
  assertEquals(expected, JSON.stringify(input));
  assertEquals(expected, JSON.stringify(input, (key, value) => value));
  assertEquals(JSON.stringify(input, null, "="),
               JSON.stringify(input, (key, value) => value, "="));
}

TestStringify("true", true);
TestStringify("false", false);
TestStringify("null", null);
TestStringify("false", {toJSON: function () { return false; }});
TestStringify("4", 4);
TestStringify('"foo"', "foo");
TestStringify("null", Infinity);
TestStringify("null", -Infinity);
TestStringify("null", NaN);
TestStringify("4", new Number(4));
TestStringify('"bar"', new String("bar"));

TestStringify('"foo\\u0000bar"', "foo\0bar");
TestStringify('"f\\"o\'o\\\\b\\ba\\fr\\nb\\ra\\tz"',
              "f\"o\'o\\b\ba\fr\nb\ra\tz");

TestStringify("[1,2,3]", [1, 2, 3]);
assertEquals("[\n 1,\n 2,\n 3\n]", JSON.stringify([1, 2, 3], null, 1));
assertEquals("[\n  1,\n  2,\n  3\n]", JSON.stringify([1, 2, 3], null, 2));
assertEquals("[\n  1,\n  2,\n  3\n]",
             JSON.stringify([1, 2, 3], null, new Number(2)));
assertEquals("[\n^1,\n^2,\n^3\n]", JSON.stringify([1, 2, 3], null, "^"));
assertEquals("[\n^1,\n^2,\n^3\n]",
             JSON.stringify([1, 2, 3], null, new String("^")));
assertEquals("[\n 1,\n 2,\n [\n  3,\n  [\n   4\n  ],\n  5\n ],\n 6,\n 7\n]",
             JSON.stringify([1, 2, [3, [4], 5], 6, 7], null, 1));
assertEquals("[]", JSON.stringify([], null, 1));
assertEquals("[1,2,[3,[4],5],6,7]",
             JSON.stringify([1, 2, [3, [4], 5], 6, 7], null));
assertEquals("[2,4,[6,[8],10],12,14]",
             JSON.stringify([1, 2, [3, [4], 5], 6, 7], DoubleNumbers));
TestStringify('["a","ab","abc"]', ["a","ab","abc"]);
TestStringify('{"a":1,"c":true}', { a : 1,
                                    b : function() { 1 },
                                    c : true,
                                    d : function() { 2 } });
TestStringify('[1,null,true,null]',
              [1, function() { 1 }, true, function() { 2 }]);
TestStringify('"toJSON 123"',
              { toJSON : function() { return 'toJSON 123'; } });
TestStringify('{"a":321}',
              { a : { toJSON : function() { return 321; } } });
var counter = 0;
assertEquals('{"getter":123}',
             JSON.stringify({ get getter() { counter++; return 123; } }));
assertEquals(1, counter);
assertEquals('{"getter":123}',
             JSON.stringify({ get getter() { counter++; return 123; } },
                            null,
                            0));
assertEquals(2, counter);

TestStringify('{"a":"abc","b":"\u1234bc"}',
              { a : "abc", b : "\u1234bc" });


var a = { a : 1, b : 2 };
delete a.a;
TestStringify('{"b":2}', a);

var b = {};
b.__proto__ = { toJSON : function() { return 321;} };
TestStringify("321", b);

var array = [""];
var expected = '""';
for (var i = 0; i < 10000; i++) {
  array.push("");
  expected = '"",' + expected;
}
expected = '[' + expected + ']';
TestStringify(expected, array);


var circular = [1, 2, 3];
circular[2] = circular;
assertThrows(function () { JSON.stringify(circular); }, TypeError);
assertThrows(function () { JSON.stringify(circular, null, 0); }, TypeError);

var singleton = [];
var multiOccurrence = [singleton, singleton, singleton];
TestStringify("[[],[],[]]", multiOccurrence);

TestStringify('{"x":5,"y":6}', {x:5,y:6});
assertEquals('{"x":5}', JSON.stringify({x:5,y:6}, ['x']));
assertEquals('{\n "a": "b",\n "c": "d"\n}',
             JSON.stringify({a:"b",c:"d"}, null, 1));
assertEquals('{"y":6,"x":5}', JSON.stringify({x:5,y:6}, ['y', 'x']));
assertEquals('{"y":6,"x":5}', JSON.stringify({x:5,y:6}, ['y', 'x', 'x', 'y']));

// toJSON get string keys.
var checker = {};
var array = [checker];
checker.toJSON = function(key) { return 1 + key; };
TestStringify('["10"]', array);

// The gap is capped at ten characters if specified as string.
assertEquals('{\n          "a": "b",\n          "c": "d"\n}',
              JSON.stringify({a:"b",c:"d"}, null,
                             "          /*characters after 10th*/"));

//The gap is capped at ten characters if specified as number.
assertEquals('{\n          "a": "b",\n          "c": "d"\n}',
              JSON.stringify({a:"b",c:"d"}, null, 15));

// Replaced wrapped primitives are unwrapped.
function newx(k, v)  { return (k == "x") ? new v(42) : v; }
assertEquals('{"x":"42"}', JSON.stringify({x: String}, newx));
assertEquals('{"x":42}', JSON.stringify({x: Number}, newx));
assertEquals('{"x":true}', JSON.stringify({x: Boolean}, newx));

TestStringify(undefined, undefined);
TestStringify(undefined, function () { });
// Arrays with missing, undefined or function elements have those elements
// replaced by null.
TestStringify("[null,null,null]", [undefined,,function(){}]);

// Objects with undefined or function properties (including replaced properties)
// have those properties ignored.
assertEquals('{}',
             JSON.stringify({a: undefined, b: function(){}, c: 42, d: 42},
                            function(k, v) { if (k == "c") return undefined;
                                             if (k == "d") return function(){};
                                             return v; }));

TestInvalid('1); throw "foo"; (1');

var x = 0;
eval("(1); x++; (1)");
TestInvalid('1); x++; (1');

// Test string conversion of argument.
var o = { toString: function() { return "42"; } };
assertEquals(42, JSON.parse(o));


for (var i = 0x0000; i <= 0xFFFF; i++) {
  var string = String.fromCharCode(i);
  var encoded = JSON.stringify(string);
  var expected = 'uninitialized';
  // Following the ES5 specification of the abstraction function Quote.
  if (string == '"' || string == '\\') {
    // Step 2.a
    expected = '\\' + string;
  } else if ("\b\t\n\r\f".includes(string)) {
    // Step 2.b
    if (string == '\b') expected = '\\b';
    else if (string == '\t') expected = '\\t';
    else if (string == '\n') expected = '\\n';
    else if (string == '\f') expected = '\\f';
    else if (string == '\r') expected = '\\r';
  } else if (i < 0x20 || (i >= 0xD800 && i <= 0xDFFF)) {
    // Step 2.c
    expected = '\\u' + i.toString(16).padStart(4, '0');
  } else {
    expected = string;
  }
  assertEquals('"' + expected + '"', encoded, "code point " + i);
}


// Ensure that wrappers and callables are handled correctly.
var num37 = new Number(42);
num37.valueOf = function() { return 37; };

var numFoo = new Number(42);
numFoo.valueOf = "not callable";
numFoo.toString = function() { return "foo"; };

var numTrue = new Number(42);
numTrue.valueOf = function() { return true; }

var strFoo = new String("bar");
strFoo.toString = function() { return "foo"; };

var str37 = new String("bar");
str37.toString = "not callable";
str37.valueOf = function() { return 37; };

var strTrue = new String("bar");
strTrue.toString = function() { return true; }

var func = function() { /* Is callable */ };

var funcJSON = function() { /* Is callable */ };
funcJSON.toJSON = function() { return "has toJSON"; };

var re = /Is callable/;

var reJSON = /Is callable/;
reJSON.toJSON = function() { return "has toJSON"; };

TestStringify('[37,null,1,"foo","37","true",null,"has toJSON",{},"has toJSON"]',
              [num37, numFoo, numTrue,
               strFoo, str37, strTrue,
               func, funcJSON, re, reJSON]);


var oddball = Object(42);
oddball.__proto__ = { __proto__: null, toString: function() { return true; } };
TestStringify('1', oddball);

var getCount = 0;
var callCount = 0;
var counter = { get toJSON() { getCount++;
                               return function() { callCount++;
                                                   return 42; }; } };

// RegExps are not callable, so they are stringified as objects.
TestStringify('{}', /regexp/);
TestStringify('42', counter);
assertEquals(4, getCount);
assertEquals(4, callCount);

var oddball2 = Object(42);
var oddball3 = Object("foo");
oddball3.__proto__ = { __proto__: null,
                       toString: "not callable",
                       valueOf: function() { return true; } };
oddball2.__proto__ = { __proto__: null,
                       toJSON: function () { return oddball3; } }
TestStringify('"true"', oddball2);


var falseNum = Object("37");
falseNum.__proto__ = Number.prototype;
falseNum.toString = function() { return 42; };
TestStringify('"42"', falseNum);

// Parse an object value as __proto__.
var o1 = JSON.parse('{"__proto__":[]}');
assertEquals([], o1.__proto__);
assertEquals(["__proto__"], Object.keys(o1));
assertEquals([], Object.getOwnPropertyDescriptor(o1, "__proto__").value);
assertEquals(["__proto__"], Object.getOwnPropertyNames(o1));
assertTrue(o1.hasOwnProperty("__proto__"));
assertTrue(Object.prototype.isPrototypeOf(o1));

// Parse a non-object value as __proto__.
var o2 = JSON.parse('{"__proto__":5}');
assertEquals(5, o2.__proto__);
assertEquals(["__proto__"], Object.keys(o2));
assertEquals(5, Object.getOwnPropertyDescriptor(o2, "__proto__").value);
assertEquals(["__proto__"], Object.getOwnPropertyNames(o2));
assertTrue(o2.hasOwnProperty("__proto__"));
assertTrue(Object.prototype.isPrototypeOf(o2));

var json = '{"stuff before slash\\\\stuff after slash":"whatever"}';
TestStringify(json, JSON.parse(json));


// https://bugs.chromium.org/p/v8/issues/detail?id=3139

reviver = function(p, v) {
  if (p == "a") {
    this.b = { get x() {return null}, set x(_){throw 666} }
  }
  return v;
}
assertEquals({a: 0, b: {x: null}}, JSON.parse('{"a":0,"b":1}', reviver));


// Make sure a failed [[Delete]] doesn't throw

reviver = function(p, v) {
  Object.freeze(this);
  return p === "" ? v : undefined;
}
assertEquals({a: 0, b: 1}, JSON.parse('{"a":0,"b":1}', reviver));


// Make sure a failed [[DefineProperty]] doesn't throw

reviver = function(p, v) {
  Object.freeze(this);
  return p === "" ? v : 42;
}
assertEquals({a: 0, b: 1}, JSON.parse('{"a":0,"b":1}', reviver));

reviver = (k, v) => (v === Infinity) ? "inf" : v;
assertEquals('{"":"inf"}', JSON.stringify({"":Infinity}, reviver));

assertEquals([10.4, "\u1234"], JSON.parse("[10.4, \"\u1234\"]"));
assertEquals(10, JSON.parse('{"10":10}')["10"]);

assertEquals(`[
          1,
          2
]`, JSON.stringify([1,2], undefined, 1000000000000000));