Who does *really* do Test-Driven Development? Probably only a small minority. The presentation shows what code leads to complex tests and what you have to consider to make writing tests much easier - because not doing TDD is no excuse for not having tests at all.

1. Things to consider for testable code Frank Kleine, 27.10.2009

4. Business logic

5. Logging

6. Error handling

7. Environment handling

8. Didn't we forget something really important?

9. Construction of Objects!

34. Singleton with DI framework $binder->bind('Session') ->to('PhpSession')

35. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') Configure the binding

36. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') ->in(stubBindingScopes::$SINGLETON); Configure the binding Enforce singletoness: DI framework will only create one instance of PhpSession and inject always this same instance

37. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') ->in(stubBindingScopes::$SINGLETON); class Processor { protected $session; /** * @Inject */ public function __construct(Session $session) { $this->session = $session; } … } Configure the binding Enforce singletoness: DI framework will only create one instance of PhpSession and inject always this same instance

38. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') ->in(stubBindingScopes::$SINGLETON); class Processor { protected $session; /** * @Inject */ public function __construct(Session $session) { $this->session = $session; } … } Configure the binding Enforce singletoness: DI framework will only create one instance of PhpSession and inject always this same instance Dependency Injection

39. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') ->in(stubBindingScopes::$SINGLETON); class Processor { protected $session; /** * @Inject */ public function __construct(Session $session) { $this->session = $session; } … } Configure the binding Enforce singletoness: DI framework will only create one instance of PhpSession and inject always this same instance Dependency Injection Tell DI framework to inject required parameters on creation of Processor

40. Singleton with DI framework $binder->bind('Session') ->to('PhpSession') ->in(stubBindingScopes::$SINGLETON); class Processor { protected $session; /** * @Inject */ public function __construct(Session $session) { $this->session = $session; } … } Configure the binding Enforce singletoness: DI framework will only create one instance of PhpSession and inject always this same instance Dependency Injection Piece of cake to test: independent of PhpSession Tell DI framework to inject required parameters on creation of Processor

52. Modify

53. Simplify Modify

54. Simplify Improve Modify

56. Singletons are really, really (and I mean really)

57. Singletons are really, really (and I mean really) EVIL