function description(msg)
{
    print(msg);
    print("\nOn success, you will see a series of \"PASS\" messages, followed by \"TEST COMPLETE\".\n");
    print();
}

function debug(msg)
{
    print(msg);
}

function escapeString(text)
{
    return text.replace(/\0/g, "");
}

function testPassed(msg)
{
    print("PASS", escapeString(msg));
}

function testFailed(msg)
{
    print("FAIL", escapeString(msg));
}

function areArraysEqual(_a, _b)
{
    if (Object.prototype.toString.call(_a) != Object.prototype.toString.call([]))
        return false;
    if (_a.length !== _b.length)
        return false;
    for (var i = 0; i < _a.length; i++)
        if (_a[i] !== _b[i])
            return false;
    return true;
}

function isMinusZero(n)
{
    // the only way to tell 0 from -0 in JS is the fact that 1/-0 is
    // -Infinity instead of Infinity
    return n === 0 && 1/n < 0;
}

function isResultCorrect(_actual, _expected)
{
    if (_expected === 0)
        return _actual === _expected && (1/_actual) === (1/_expected);
    if (_actual === _expected)
        return true;
    if (typeof(_expected) == "number" && isNaN(_expected))
        return typeof(_actual) == "number" && isNaN(_actual);
    if (Object.prototype.toString.call(_expected) == Object.prototype.toString.call([]))
        return areArraysEqual(_actual, _expected);
    return false;
}

function stringify(v)
{
    if (v === 0 && 1/v < 0)
        return "-0";
    else return "" + v;
}

function shouldBe(_a, _b)
{
  if (typeof _a != "string" || typeof _b != "string")
    debug("WARN: shouldBe() expects string arguments");
  var exception;
  var _av;
  try {
     _av = eval(_a);
  } catch (e) {
     exception = e;
  }
  var _bv = eval(_b);

  if (exception)
    testFailed(_a + " should be " + _bv + ". Threw exception " + exception);
  else if (isResultCorrect(_av, _bv))
    testPassed(_a + " is " + _b);
  else if (typeof(_av) == typeof(_bv))
    testFailed(_a + " should be " + _bv + ". Was " + stringify(_av) + ".");
  else
    testFailed(_a + " should be " + _bv + " (of type " + typeof _bv + "). Was " + _av + " (of type " + typeof _av + ").");
}

function shouldBeTrue(_a) { shouldBe(_a, "true"); }
function shouldBeFalse(_a) { shouldBe(_a, "false"); }
function shouldBeNaN(_a) { shouldBe(_a, "NaN"); }
function shouldBeNull(_a) { shouldBe(_a, "null"); }

function shouldBeEqualToString(a, b)
{
  var unevaledString = '"' + b.replace(/"/g, "\"") + '"';
  shouldBe(a, unevaledString);
}

function shouldBeUndefined(_a)
{
  var exception;
  var _av;
  try {
     _av = eval(_a);
  } catch (e) {
     exception = e;
  }

  if (exception)
    testFailed(_a + " should be undefined. Threw exception " + exception);
  else if (typeof _av == "undefined")
    testPassed(_a + " is undefined.");
  else
    testFailed(_a + " should be undefined. Was " + _av);
}


function shouldThrow(_a, _e)
{
  var exception;
  var _av;
  try {
     _av = eval(_a);
  } catch (e) {
     exception = e;
  }

  var _ev;
  if (_e)
      _ev =  eval(_e);

  if (exception) {
    if (typeof _e == "undefined" || exception == _ev)
      testPassed(_a + " threw exception " + exception + ".");
    else
      testFailed(_a + " should throw " + (typeof _e == "undefined" ? "an exception" : _ev) + ". Threw exception " + exception + ".");
  } else if (typeof _av == "undefined")
    testFailed(_a + " should throw " + (typeof _e == "undefined" ? "an exception" : _ev) + ". Was undefined.");
  else
    testFailed(_a + " should throw " + (typeof _e == "undefined" ? "an exception" : _ev) + ". Was " + _av + ".");
}