index.js

var BSONExt = require('bindings')('bson').BSON;
var jsBson = require('bson');
const BSON = new BSONExt([
  jsBson.Binary,
  jsBson.Code,
  jsBson.DBRef,
  jsBson.Decimal128,
  jsBson.Double,
  jsBson.Int32,
  jsBson.Long,
  jsBson.Map,
  jsBson.MaxKey,
  jsBson.MinKey,
  jsBson.ObjectId,
  jsBson.BSONRegExp,
  jsBson.BSONSymbol,
  jsBson.Timestamp
]);

// BSON MAX VALUES
BSON.BSON_INT32_MAX = 0x7fffffff;
BSON.BSON_INT32_MIN = -0x80000000;

BSON.BSON_INT64_MAX = Math.pow(2, 63) - 1;
BSON.BSON_INT64_MIN = -Math.pow(2, 63);

// JS MAX PRECISE VALUES
BSON.JS_INT_MAX = 0x20000000000000; // Any integer up to 2^53 can be precisely represented by a double.
BSON.JS_INT_MIN = -0x20000000000000; // Any integer down to -2^53 can be precisely represented by a double.

// Decorate BSON with types from js-bson
[
  'Binary',
  'Code',
  'DBRef',
  'Decimal128',
  'Double',
  'Int32',
  'Long',
  'Map',
  'MaxKey',
  'MinKey',
  'ObjectId',
  'BSONRegExp',
  'Symbol',
  'Timestamp'
].forEach(function(type) {
  BSON[type] = jsBson[type];
});

// special case for deprecated names
BSON.ObjectID = BSON.ObjectId;

// Just add constants to the Native BSON parser
BSON.BSON_BINARY_SUBTYPE_DEFAULT = 0;
BSON.BSON_BINARY_SUBTYPE_FUNCTION = 1;
BSON.BSON_BINARY_SUBTYPE_BYTE_ARRAY = 2;
BSON.BSON_BINARY_SUBTYPE_UUID = 3;
BSON.BSON_BINARY_SUBTYPE_MD5 = 4;
BSON.BSON_BINARY_SUBTYPE_USER_DEFINED = 128;

// Return the BSON
module.exports = BSON;