Ship 10 Times Faster With These Designs

Your competition will hate you. By the time they release one feature with a ton of bugs, you would have released 10 features with no bugs. A good design makes a world of difference in terms of ease of change, teamwork, testability, reliability and overall quality of life. I will present a software design approach that allowed my teams to ship unbelievably fast while keeping the quality above industry standards.

Transcript

1. Ship 10 Times Faster With These Designs CONFOO 2021 | FEB 25, 2021 @afilina
2. Anna Filina / @afilina • Coding since 1997. • PHP since 2003. • Legacy archaeology. • Test automation. • Talks and workshops. • YouTube videos. • Filina Consulting.
3. Your competition will hate you. By the time they release one feature with a ton of bugs, you would have released 10 features with no bugs. A good design makes a world of difference in terms of ease of change, teamwork, testability, reliability and overall quality of life. I will present a software design approach that allowed my teams to ship unbelievably fast while keeping the quality above industry standards.
4. Waiting for all the information before starting work.
5. Knowns • Payment Provider • Charge money • Refund money of a previous transaction
6. Payment Provider charge
7. Payment Provider charge (Money, Instrument) refund
8. Payment Provider charge (Money, Instrument) refund (Money, PaymentId)
9. Payment Provider charge (Money, Instrument) : PaymentId refund (Money, PaymentId)
10. Payment Provider charge (Money, Instrument) : PaymentId refund (Money, PaymentId) : RefundId
11. interface PaymentProvider { public function charge(Money $money, Instrument $instrument): PaymentId; }
12. Are we able to use this interface?
13. Submit Form field Form field POST /payments/capture
14. Validate input Controller Charge via PaymentProvider Request Response Send output
15. final class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { } }
16. final class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $paymentId = $this->paymentProvider->charge($money, $instrument); } }
17. final class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); $paymentId = $this->paymentProvider->charge($money, $instrument); } }
18. final class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); $paymentId = $this->paymentProvider->charge($money, $instrument); return $this->createSuccessResponse($paymentId); } }
19. { "instrument": { //... }, "money": { "currency": "USD", "amount": 1050 } } { "paymentId": "CC-0001" }
20. FE/BE Contract • Is input viable? • Is output viable? • Talk use cases.
21. Waiting for all the information before starting work. Postpone decisions using interfaces. Write code for the things that you do know. Validate assumptions using code. Uncover new information or use cases.
22. Can't have multiple developers on one feature.
23. class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); $paymentId = $this->paymentProvider->charge($money, $instrument); return $this->createSuccessResponse($paymentId); } }
24. class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); $paymentId = $this->paymentProvider->charge($money, $instrument); return $this->createSuccessResponse($paymentId); } }
25. class CapturePaymentHandler { public function handle(ServerRequestInterface $request): ResponseInterface { $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); $paymentId = $this->paymentProvider->charge($money, $instrument); return $this->createSuccessResponse($paymentId); } }
26. interface PaymentProvider { /** * @throws ChargeFailed */ public function charge(Money $money, Instrument $instrument): PaymentId; }
27. $money = Money::fromRequest($request); $instrument = Instrument::fromRequest($request); try { $paymentId = $this->paymentProvider->charge($money, $instrument); } catch (ChargeFailed $exception) { return $this->createErrorResponse($exception->getMessage()); } return $this->createSuccessResponse($paymentId);
28. Handlers + tests PaymentProvider implementation + tests Acceptance tests + wiring components Value objects + tests POST /payments/capture
29. Can't have multiple developers on one feature. Create separate classes with clear contracts.
30. We don't understand the domain.
31. charge($money, $instrument) Money int $amount string $currency charge(int $amount, string $currency, string $cardNumber, string $cardExpiry, string $postalCode, …) Instrument Card $card Address $address
32. PaymentProvider HttpClient send (Request) charge (Money, Instrument)
33. Money Instrument PaymentProvider Domain
34. Money Instrument PaymentProvider CapturePaymentHandler Application
35. Money Instrument PaymentProvider CapturePaymentHandler HttpClient Infrastructure
36. Create Small Classes & Methods • 10 statements per method. • Classes that can fit in your head.
37. We don't understand the domain. Separate the domain from the other layers. Create small classes and methods.
38. Bugs.
39. Money Instrument PaymentProvider CapturePaymentHandler HttpClient Unit tests Unit tests Integration tests Acceptance tests
40. final class CapturePaymentHandler { private StripePaymentProvider $paymentProvider; public function __construct() { $this->paymentProvider = new StripePaymentProvider(); } }
41. final class CapturePaymentHandler { private PaymentProvider $paymentProvider; public function __construct(PaymentProvider $paymentProvider) { $this->paymentProvider = $paymentProvider; } } final class CapturePaymentHandler { private StripePaymentProvider $paymentProvider; public function __construct() { $this->paymentProvider = new StripePaymentProvider(); } }
42. final class CapturePaymentHandlerTest extends TestCase { protected function setUp(): void { $this->paymentProvider = $this->createMock(PaymentProvider::class); $this->capturePaymentHandler = new CapturePaymentHandler( $this->paymentProvider ); } }
43. Bugs. Just write tests. Learn to write even better tests.
44. @afilina