Faker\Calculator\Luhn::isValid PHP Method

    public static function isValid($number)
    {
        return self::checksum($number) === 0;
    }

 public function testSirenReturnsAWellFormattedSiren()
 {
     $siren = $this->faker->siren();
     $this->assertRegExp("/^\\d{3}\\s\\d{3}\\s\\d{3}\$/", $siren);
     $siren = str_replace(' ', '', $siren);
     $this->assertTrue(Luhn::isValid($siren));
 }