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<?php
declare(strict_types=1);
namespace Damax\ChargeableApi;
final class Credit
{
private $value;
public static function blank(): self
return self::fromInteger(0);
}
public static function fromInteger(int $value): self
return new self($value);
public function add(self $credit): self
return new self($this->value + $credit->value);
/**
* @throws InvalidOperation
*/
public function subtract(self $credit): self
if ($credit->value > $this->value) {
throw InsufficientFunds::notEnough($credit->value - $this->value);
return new self($this->value - $credit->value);
public function toInteger(): int
return $this->value;
private function __construct(int $value)
if ($value < 0) {
throw InvalidOperation::negativeCredit();
$this->value = $value;
damax-solutions /
php-chargeable-api
