json-bigint-patch

JSON.parse/stringify with bigints support. Based on Douglas Crockford JSON.js package and BigInt feature of JavaScript.

While most JSON parsers assume numeric values have same precision restrictions as IEEE 754 double, JSON specification does not say anything about number precision. Any floating point number in decimal (optionally scientific) notation is valid JSON value. It's a good idea to serialize values which might fall out of IEEE 754 integer precision as strings in your JSON api, but { "value" : 9223372036854775807}, for example, is still a valid RFC4627 JSON string, and in most JS runtimes the result of JSON.parse is this object: { value: 9223372036854776000 }

==========

example:

var json = '{ "value" : 9223372036854775807, "v2": 123 }';
console.log('Input:', json);
console.log('');

console.log('JavaScript built-in JSON:')
var r = JSON.parse(json);
console.log('Native JSON.parse(input).value : ', r.value.toString());
console.log('Native JSON.stringify(JSON.parse(input)):', JSON.stringify(r));

require('json-bigint-patch');

console.log('\n\nPatched JSON:');
var r1 = JSON.parse(json);
console.log('Patched JSON.parse(input).value : ', r1.value.toString());
console.log('Patched JSON.stringify(JSON.parse(input)):', JSON.stringify(r1));

Output:

Input: { "value" : 9223372036854775807, "v2": 123 }

JavaScript built-in JSON:
Native JSON.parse(input).value :  9223372036854776000
Native JSON.stringify(JSON.parse(input)): {"value":9223372036854776000,"v2":123}


Patched JSON:
Patched JSON.parse(input).value :  9223372036854775807
Patched JSON.stringify(JSON.parse(input)): {"value":9223372036854775807,"v2":123}

Links:

• RFC4627: The application/json Media Type for JavaScript Object Notation (JSON)
• Re: [Json] Limitations on number size?
• Is there any proper way to parse JSON with large numbers? (long, bigint, int64)
• What is JavaScript's Max Int? What's the highest Integer value a Number can go to without losing precision?
• Large numbers erroneously rounded in Javascript