public function testIsNumber()
{
// from js
$this->assertFalse(__u::isNumber('string'), 'a string is not a number');
$this->assertFalse(__u::isNumber(null), 'null is not a number');
$this->assertTrue(__u::isNumber(3 * 4 - 7 / 10), 'but numbers are');
// extra
$this->assertFalse(__u::isNumber(acos(8)), 'invalid calculations (nan) are not numbers');
$this->assertFalse(__u::isNumber('1'), 'strings of numbers are not numbers');
$this->assertFalse(__u::isNumber(log(0)), 'infinite values are not numbers');
$this->assertTrue(__u::isNumber(pi()));
$this->assertTrue(__u::isNumber(M_PI));
$this->assertFalse(__u(acos(8))->isNumber());
$this->assertFalse(__u('1')->isNumber());
$this->assertFalse(__u(log(0))->isNumber());
$this->assertTrue(__u(pi())->isNumber());
$this->assertTrue(__u(M_PI)->isNumber());
$this->assertTrue(__u(1)->isNumber());
// docs
$this->assertTrue(__u::isNumber(1));
$this->assertTrue(__u::isNumber(2.5));
$this->assertFalse(__u::isNumber('5'));
}
