Flipping the Koin

Slides of the talk I gave at Kotlin/Everywhere in Stockholm, St. Petersburg and Milan

Transcript

1. R O B E R T O O R G I U - @ _ t i w i z
   Flippin’ the Koin
   

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2. Is there a difference?
   IMPLEMENTATION
   DI vs SL
   

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3. DI Container
   Should only call itself Never called by others
   Constructs objects
   

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4. Service Locator
   Container Dependency
   

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5. I’m not really answering this question
   WHAT IS DAGGER?
   

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6. @Inject
   lateinit var myTarget: Target
   myComponent.inject(this)
   val myTarget =
   myComponent.getTarget()
   

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7. insert-koin.io
   

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8. Why I like it
   Kotlin DSL Quick setup Easy to follow
   

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9. I’m not really answering this question either
   WHAT IS KOIN?
   

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10. private val target: Target
    by inject()
    inline fun
    ComponentCallbacks.inject()
    

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11. modules
    declaration
    val myModule = module {
    single { TargetImpl() }
    factory { (view: View) ->
    Presenter(view, get() }
    viewModel { MyViewModel(get()) }
    }
    

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12. Injection
    private val target: Target
    by inject { parametersOf(this) }
    

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13. Injection
    private val target: Target
    by inject { parametersOf(this) }
    

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14. Injection
    private val target: Target
    by inject { parametersOf(this) }
    

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15. Injection
    val viewModel: MyViewModel by viewModel()
    

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16. Injection
    class MyWorker : KoinComponent {
    override suspend fun doWork(): Result {
    val target: Target by inject()
    ...
    }
    }
    

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17. Application
    startKoin {
    androidContext(context)
    androidLogger()
    modules(
    listOf(module1,..., moduleN)
    )
    }
    

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18. Let’s talk
    about testing
    “
    

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19. JUnit + KoinTest
    

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20. Dependencies
    koinApplication {
    androidContext(context)
    modules(fetchModules())
    }.checkModules()
    

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21. Dependencies
    koinApplication {
    androidContext(context)
    modules(fetchModules())
    }.checkModules
    {
    create {
    parametersOf(mock1,...,paramN)
    }
    }
    

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22. Building a test
    

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23. startKoin
    class MyTest : KoinTest {
    @Before
    fun setup() {
    startKoin {
    androidContext(context)
    modules(fetchModules())
    }
    }
    }
    

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24. startKoin
    class MyTest : KoinTest {
    @Before
    fun setup() {
    startKoin {
    androidContext(context)
    modules(fetchModules())
    }
    }
    }
    

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25. startKoin stopKoin
    class MyTest : KoinTest {
    @After
    fun tearDown() {
    stopKoin()
    }
    }
    

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26. startKoin stopKoin
    class MyTest : KoinTest {
    @After
    fun tearDown() {
    stopKoin()
    }
    }
    

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27. startKoin stopKoin Test
    

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28. class MyTest : KoinTest {
    @Before
    fun setup() {
    startKoin {...}
    }
    @Test
    fun my_test() {
    }
    }
    

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29. class MyTest : KoinTest {
    @Before
    fun setup() {
    startKoin {...}
    }
    @Test
    fun my_test() {
    }
    }
    private val target: Target by inject()
    declareMock()
    given(target).will { throw Exception() }
    

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30. Dagger
    VS
    Koin
    

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31. WARNING:
    Opinionated
    Ideas ahead
    

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32. We should use
    Dagger
    

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33. Quick setup
    

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34. Compile time
    safety
    Because we all love it.
    

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35. Scalability
    

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36. Maintainability
    

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37. Any
    questions?
    “
    

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38. Use the tools
    You
    Like the most
    

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39. Thanks!
    

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