node/test/simple/test-writedouble.js

/*
 * Tests to verify we're writing doubles correctly
 */
var ASSERT = require('assert');

function test() {
  var buffer = new Buffer(16);
  buffer.writeDouble(2.225073858507201e-308, 0, 'big');
  buffer.writeDouble(2.225073858507201e-308, 8, 'little');
  ASSERT.equal(0x00, buffer[0]);
  ASSERT.equal(0x0f, buffer[1]);
  ASSERT.equal(0xff, buffer[2]);
  ASSERT.equal(0xff, buffer[3]);
  ASSERT.equal(0xff, buffer[4]);
  ASSERT.equal(0xff, buffer[5]);
  ASSERT.equal(0xff, buffer[6]);
  ASSERT.equal(0xff, buffer[7]);
  ASSERT.equal(0xff, buffer[8]);
  ASSERT.equal(0xff, buffer[9]);
  ASSERT.equal(0xff, buffer[10]);
  ASSERT.equal(0xff, buffer[11]);
  ASSERT.equal(0xff, buffer[12]);
  ASSERT.equal(0xff, buffer[13]);
  ASSERT.equal(0x0f, buffer[14]);
  ASSERT.equal(0x00, buffer[15]);

  buffer.writeDouble(1.0000000000000004, 0, 'big');
  buffer.writeDouble(1.0000000000000004, 8, 'little');
  ASSERT.equal(0x3f, buffer[0]);
  ASSERT.equal(0xf0, buffer[1]);
  ASSERT.equal(0x00, buffer[2]);
  ASSERT.equal(0x00, buffer[3]);
  ASSERT.equal(0x00, buffer[4]);
  ASSERT.equal(0x00, buffer[5]);
  ASSERT.equal(0x00, buffer[6]);
  ASSERT.equal(0x02, buffer[7]);
  ASSERT.equal(0x02, buffer[8]);
  ASSERT.equal(0x00, buffer[9]);
  ASSERT.equal(0x00, buffer[10]);
  ASSERT.equal(0x00, buffer[11]);
  ASSERT.equal(0x00, buffer[12]);
  ASSERT.equal(0x00, buffer[13]);
  ASSERT.equal(0xf0, buffer[14]);
  ASSERT.equal(0x3f, buffer[15]);

  buffer.writeDouble(-2, 0, 'big');
  buffer.writeDouble(-2, 8, 'little');
  ASSERT.equal(0xc0, buffer[0]);
  ASSERT.equal(0x00, buffer[1]);
  ASSERT.equal(0x00, buffer[2]);
  ASSERT.equal(0x00, buffer[3]);
  ASSERT.equal(0x00, buffer[4]);
  ASSERT.equal(0x00, buffer[5]);
  ASSERT.equal(0x00, buffer[6]);
  ASSERT.equal(0x00, buffer[7]);
  ASSERT.equal(0x00, buffer[8]);
  ASSERT.equal(0x00, buffer[9]);
  ASSERT.equal(0x00, buffer[10]);
  ASSERT.equal(0x00, buffer[11]);
  ASSERT.equal(0x00, buffer[12]);
  ASSERT.equal(0x00, buffer[13]);
  ASSERT.equal(0x00, buffer[14]);
  ASSERT.equal(0xc0, buffer[15]);

  buffer.writeDouble(1.7976931348623157e+308, 0, 'big');
  buffer.writeDouble(1.7976931348623157e+308, 8, 'little');
  ASSERT.equal(0x7f, buffer[0]);
  ASSERT.equal(0xef, buffer[1]);
  ASSERT.equal(0xff, buffer[2]);
  ASSERT.equal(0xff, buffer[3]);
  ASSERT.equal(0xff, buffer[4]);
  ASSERT.equal(0xff, buffer[5]);
  ASSERT.equal(0xff, buffer[6]);
  ASSERT.equal(0xff, buffer[7]);
  ASSERT.equal(0xff, buffer[8]);
  ASSERT.equal(0xff, buffer[9]);
  ASSERT.equal(0xff, buffer[10]);
  ASSERT.equal(0xff, buffer[11]);
  ASSERT.equal(0xff, buffer[12]);
  ASSERT.equal(0xff, buffer[13]);
  ASSERT.equal(0xef, buffer[14]);
  ASSERT.equal(0x7f, buffer[15]);

  buffer.writeDouble(0*-1, 0, 'big');
  buffer.writeDouble(0*-1, 8, 'little');
  ASSERT.equal(0x80, buffer[0]);
  ASSERT.equal(0x00, buffer[1]);
  ASSERT.equal(0x00, buffer[2]);
  ASSERT.equal(0x00, buffer[3]);
  ASSERT.equal(0x00, buffer[4]);
  ASSERT.equal(0x00, buffer[5]);
  ASSERT.equal(0x00, buffer[6]);
  ASSERT.equal(0x00, buffer[7]);
  ASSERT.equal(0x00, buffer[8]);
  ASSERT.equal(0x00, buffer[9]);
  ASSERT.equal(0x00, buffer[10]);
  ASSERT.equal(0x00, buffer[11]);
  ASSERT.equal(0x00, buffer[12]);
  ASSERT.equal(0x00, buffer[13]);
  ASSERT.equal(0x00, buffer[14]);
  ASSERT.equal(0x80, buffer[15]);
}


test();