public function testSetDefaultScale() { $this->if($scale = 8)->when(Decimal::setDefaultScale($scale))->then->variable(Decimal::defaultScale())->isEqualTo($scale)->if($invalidScale = 8.1)->then->exception(function () use($invalidScale) { Decimal::setDefaultScale($invalidScale); })->isInstanceOf(\InvalidArgumentException::class)->if($negativeScale = -2)->then->exception(function () use($negativeScale) { Decimal::setDefaultScale($negativeScale); })->isInstanceOf(\InvalidArgumentException::class); }