math.frexp = function(x) {
_checkFloat(x);
var xx = x.__float__().val;
// check for 0, -0, NaN, Inf, -Inf
if (xx === 0 || !isFinite(xx)) {
return new types.Tuple([x.__float__(), new types.Int(0)]);
}
var buff = new Buffer(8);
buff.writeDoubleLE(x, 0);
var a = buff.readUInt32LE(0);
var b = buff.readUInt32LE(4);
var exp = ((b >> 20) & 0x7ff) - 1022;
var num;
// check for denormal number
if (exp == -1022) {
// each leading zero increases the exponent
num = (b & 0xfffff) * 4294967296 + a;
while ((num != 0) && (num < 0x8000000000000)) {
exp--;
num *= 2;
}
num = num / 0x10000000000000;
} else {
num = 0x10000000000000 + (b & 0xfffff) * 4294967296 + a;
num = num / 0x20000000000000;
}
if (b >> 31) {
num = -num;
}
return new types.Tuple([new types.Float(num), new types.Int(exp)]);
}
assert.equal(written, 2);
assert.equal(buf[0], 0x61);
assert.equal(buf[1], 0x00);
assert.equal(buf[2], 0xFF);
assert.equal(buf[3], 0xFF);
});
}
{
// test offset returns are correct
const b = new Buffer(16);
assert.equal(4, b.writeUInt32LE(0, 0));
assert.equal(6, b.writeUInt16LE(0, 4));
assert.equal(7, b.writeUInt8(0, 6));
assert.equal(8, b.writeInt8(0, 7));
assert.equal(16, b.writeDoubleLE(0, 8));
}
{
// test unmatched surrogates not producing invalid utf8 output
// ef bf bd = utf-8 representation of unicode replacement character
// see https://codereview.chromium.org/121173009/
const buf = new Buffer('ab\ud800cd', 'utf8');
assert.equal(buf[0], 0x61);
assert.equal(buf[1], 0x62);
assert.equal(buf[2], 0xef);
assert.equal(buf[3], 0xbf);
assert.equal(buf[4], 0xbd);
assert.equal(buf[5], 0x63);
assert.equal(buf[6], 0x64);
}
assert.throws(function() {
var buf = new Buffer(16);
buf.writeDoubleLE(0, 9);
}, RangeError);
// a slice then .parent should be undefined.
assert.equal(buf.parent, undefined);
assert.equal(buf.buffer, ab);
assert.equal(buf.length, ab.byteLength);
buf.fill(0xC);
for (let i = 0; i < LENGTH; i++) {
assert.equal(ui[i], 0xC);
ui[i] = 0xF;
assert.equal(buf[i], 0xF);
}
buf.writeUInt32LE(0xF00, 0);
buf.writeUInt32BE(0xB47, 4);
buf.writeDoubleLE(3.1415, 8);
assert.equal(dv.getUint32(0, true), 0xF00);
assert.equal(dv.getUint32(4), 0xB47);
assert.equal(dv.getFloat64(8, true), 3.1415);
// Now test protecting users from doing stupid things
assert.throws(function() {
function AB() { }
AB.__proto__ = ArrayBuffer;
AB.prototype.__proto__ = ArrayBuffer.prototype;
new Buffer(new AB());
}, TypeError);
NetWriter.prototype.writeDoubleLE = function (value) {
var buffer = new Buffer(8);
buffer.writeDoubleLE(value, 0, true);
this.content.push(buffer);
this.size += 8;
};