Remove feature output type. (#368)

* Remove feature output type. * Fix documentation.
instacart · Apr 29, 2024 · 0aa73d7 · 0aa73d7
1 parent 96df3e0
commit 0aa73d7
Show file tree

Hide file tree

Showing 16 changed files with 39 additions and 40 deletions.
diff --git a/docs/Formula-Android.md b/docs/Formula-Android.md
@@ -37,7 +37,7 @@ example, we define a `CounterFeatureFactory` which will handle `CounterKey` frag
 
 ```kotlin
 class CounterFeatureFactory : FeatureFactory<Any, CounterKey> {
-    override fun initialize(dependencies: Any, key: CounterKey): Feature<*> {
+    override fun initialize(dependencies: Any, key: CounterKey): Feature {
         val counterFormula = CounterFormula()        
         return Feature(
             state = counterFormula.toObservable(),
@@ -125,7 +125,7 @@ data class CounterKey(
 You can access the `CounterKey` within `CounterFeatureFactory`
 ```kotlin
 class CounterFeatureFactory : FeatureFactory<Any, CounterKey> {
-    override fun initialize(dependencies: Any, key: CounterKey): Feature<*> {
+    override fun initialize(dependencies: Any, key: CounterKey): Feature {
         val initialCount = key.initialCount    
         val counterFormula = CounterFormula(initialCount)        
         ...                
@@ -159,7 +159,7 @@ class CounterFeatureFactory : FeatureFactory<Dependencies, CounterKey> {
         fun counterEventRouter(): CounterEventRouter
     }
 
-    override fun initialize(dependencies: Dependencies, key: CounterKey): Feature<*> {
+    override fun initialize(dependencies: Dependencies, key: CounterKey): Feature {
         val counterEventRouter = dependencies.counterEventRouter()
         // We can pass the event router to the counter formula.
         val counterFormula = CounterFormula(counterEventRouter)        

diff --git a/formula-android-tests/src/test/java/com/instacart/formula/FragmentLifecycleTest.kt b/formula-android-tests/src/test/java/com/instacart/formula/FragmentLifecycleTest.kt
@@ -38,7 +38,7 @@ class FragmentLifecycleTest {
                     },
                     contracts =  {
                         val featureFactory = object : FeatureFactory<Unit, TestLifecycleKey> {
-                            override fun initialize(dependencies: Unit, key: TestLifecycleKey): Feature<*> {
+                            override fun initialize(dependencies: Unit, key: TestLifecycleKey): Feature {
                                 return Feature(
                                     state = Observable.empty(),
                                     viewFactory = ViewFactory.fromLayout(R.layout.test_empty_layout) {

diff --git a/formula-android-tests/src/test/java/com/instacart/formula/TestFeatureFactory.kt b/formula-android-tests/src/test/java/com/instacart/formula/TestFeatureFactory.kt
@@ -10,7 +10,7 @@ import io.reactivex.rxjava3.core.Observable
 class TestFeatureFactory<Key : FragmentKey>(
     private val state: (Key) -> Observable<Any>
 ) : FeatureFactory<Unit, Key> {
-    override fun initialize(dependencies: Unit, key: Key): Feature<*> {
+    override fun initialize(dependencies: Unit, key: Key): Feature {
         return Feature(
             state = state(key),
             viewFactory = ViewFactory.fromLayout(R.layout.test_empty_layout) {

diff --git a/formula-android/src/main/java/com/instacart/formula/android/Feature.kt b/formula-android/src/main/java/com/instacart/formula/android/Feature.kt
@@ -5,14 +5,27 @@ import io.reactivex.rxjava3.core.Observable
 /**
  * Feature is based on uni-directional state management where a single state model drives
  * the view rendering logic. It is used to support [FormulaFragment] by providing [ViewFactory]
- * and the [state] observable.
+ * and the [stateObservable] observable.
  *
  * To define a feature, we need to create a [FeatureFactory] for a specific [FragmentKey] type
  * and [bind][FragmentStoreBuilder.bind] it to the [FragmentFlowStore].
  *
  * Take a look at [FeatureFactory] for more information.
  */
-class Feature<RenderModel : Any>(
-    val state: Observable<RenderModel>,
-    val viewFactory: ViewFactory<RenderModel>
-)
+class Feature private constructor(
+    val stateObservable: Observable<Any>,
+    val viewFactory: ViewFactory<Any>
+) {
+    companion object {
+        @Suppress("UNCHECKED_CAST")
+        operator fun <RenderModel : Any> invoke(
+            state: Observable<RenderModel>,
+            viewFactory: ViewFactory<RenderModel>
+        ): Feature {
+            return Feature(
+                stateObservable = state as Observable<Any>,
+                viewFactory = viewFactory as ViewFactory<Any>,
+            )
+        }
+    }
+}
diff --git a/formula-android/src/main/java/com/instacart/formula/android/FeatureEvent.kt b/formula-android/src/main/java/com/instacart/formula/android/FeatureEvent.kt
@@ -1,7 +1,7 @@
 package com.instacart.formula.android
 
 sealed class FeatureEvent {
-    data class Init(override val id: FragmentId, val feature: Feature<*>): FeatureEvent()
+    data class Init(override val id: FragmentId, val feature: Feature): FeatureEvent()
     data class Failure(override val id: FragmentId, val error: Throwable): FeatureEvent()
     data class MissingBinding(override val id: FragmentId): FeatureEvent()
 

diff --git a/formula-android/src/main/java/com/instacart/formula/android/FeatureFactory.kt b/formula-android/src/main/java/com/instacart/formula/android/FeatureFactory.kt
@@ -12,7 +12,7 @@ package com.instacart.formula.android
  *     fun taskListInput(): TaskListFormula.Input
  *   }
  *
- *   override fun initialize(dependencies: Dependencies, key: TaskListKey): Feature<*> {
+ *   override fun initialize(dependencies: Dependencies, key: TaskListKey): Feature {
  *     // Note: we could create our own internal dagger component here using the dependencies.
  *     val formula = TaskListFormula(dependencies.taskRepo())
  *     return Feature(
@@ -40,5 +40,5 @@ interface FeatureFactory<in Dependencies, in Key : FragmentKey> {
     /**
      * Initializes state observable and a view factory for a specific [key].
      */
-    fun initialize(dependencies: Dependencies, key: Key): Feature<*>
+    fun initialize(dependencies: Dependencies, key: Key): Feature
 }
diff --git a/formula-android/src/main/java/com/instacart/formula/android/FragmentEnvironment.kt b/formula-android/src/main/java/com/instacart/formula/android/FragmentEnvironment.kt
@@ -29,7 +29,7 @@ data class FragmentEnvironment(
             factory: FeatureFactory<DependenciesT, KeyT>,
             dependencies: DependenciesT,
             key: KeyT,
-        ): Feature<*> {
+        ): Feature {
             return factory.initialize(dependencies, key)
         }
 

diff --git a/formula-android/src/main/java/com/instacart/formula/android/FragmentStoreBuilder.kt b/formula-android/src/main/java/com/instacart/formula/android/FragmentStoreBuilder.kt
@@ -71,10 +71,10 @@ class FragmentStoreBuilder<Component> {
      * @param featureFactory Feature factory that provides state observable and view rendering logic.
      */
     inline fun <reified Key: FragmentKey> bind(
-        crossinline initFeature: (Component, Key) -> Feature<*>,
+        crossinline initFeature: (Component, Key) -> Feature,
     ) = apply {
         val factory = object : FeatureFactory<Component, Key> {
-            override fun initialize(dependencies: Component, key: Key): Feature<*> {
+            override fun initialize(dependencies: Component, key: Key): Feature {
                 return initFeature(dependencies, key)
             }
         }

diff --git a/...a-android/src/main/java/com/instacart/formula/android/internal/FeatureObservableAction.kt b/...a-android/src/main/java/com/instacart/formula/android/internal/FeatureObservableAction.kt
@@ -10,13 +10,13 @@ import io.reactivex.rxjava3.core.Observable
 class FeatureObservableAction(
     private val fragmentEnvironment: FragmentEnvironment,
     private val fragmentId: FragmentId,
-    private val feature: Feature<*>,
+    private val feature: Feature,
 ) : Action<Any> {
 
     override fun key(): Any = fragmentId
 
     override fun start(send: (Any) -> Unit): Cancelable {
-        val observable = feature.state.onErrorResumeNext {
+        val observable = feature.stateObservable.onErrorResumeNext {
             fragmentEnvironment.onScreenError(fragmentId.key, it)
             Observable.empty()
         }

diff --git a/...ndroid/src/main/java/com/instacart/formula/android/internal/FormulaFragmentViewFactory.kt b/...ndroid/src/main/java/com/instacart/formula/android/internal/FormulaFragmentViewFactory.kt
@@ -17,7 +17,6 @@ internal class FormulaFragmentViewFactory(
 
     private var factory: ViewFactory<Any>? = null
 
-    @Suppress("UNCHECKED_CAST")
     override fun create(inflater: LayoutInflater, container: ViewGroup?): FeatureView<Any> {
         val key = fragmentId.key
         val featureEvent = featureProvider.getFeature(fragmentId) ?: throw IllegalStateException("Could not find feature for $key.")
@@ -29,7 +28,7 @@ internal class FormulaFragmentViewFactory(
                 throw IllegalStateException("Feature failed to initialize: $key", featureEvent.error)
             }
             is FeatureEvent.Init -> {
-                featureEvent.feature.viewFactory as ViewFactory<Any>
+                featureEvent.feature.viewFactory
             }
         }
         this.factory = viewFactory

diff --git a/formula-android/src/test/java/com/instacart/formula/android/FragmentFlowStoreTest.kt b/formula-android/src/test/java/com/instacart/formula/android/FragmentFlowStoreTest.kt
@@ -162,7 +162,7 @@ class FragmentFlowStoreTest {
 
     @Test fun `bind feature factory with to dependencies defined`() {
         val myFeatureFactory = object : FeatureFactory<String, MainKey> {
-            override fun initialize(dependencies: String, key: MainKey): Feature<*> {
+            override fun initialize(dependencies: String, key: MainKey): Feature {
                 return TestUtils.feature(
                     stateValue = dependencies
                 )
@@ -268,7 +268,7 @@ class FragmentFlowStoreTest {
     private fun FragmentKey.asRemovedEvent() = FragmentLifecycleEvent.Removed(FragmentId("", this))
 
     class TestFeatureFactory<FragmentKeyT : FragmentKey>: FeatureFactory<FakeComponent, FragmentKeyT> {
-        override fun initialize(dependencies: FakeComponent, key: FragmentKeyT): Feature<*> {
+        override fun initialize(dependencies: FakeComponent, key: FragmentKeyT): Feature {
             return Feature(
                 state = dependencies.state(key),
                 viewFactory = NoOpViewFactory()

diff --git a/formula-android/src/test/java/com/instacart/formula/android/TestUtils.kt b/formula-android/src/test/java/com/instacart/formula/android/TestUtils.kt
@@ -4,23 +4,10 @@ import com.instacart.formula.android.fakes.NoOpViewFactory
 import io.reactivex.rxjava3.core.Observable
 
 object TestUtils {
-    fun <Value : Any> feature(stateValue: Value): Feature<Value> {
+    fun <Value : Any> feature(stateValue: Value): Feature {
         return Feature(
             state = Observable.just(stateValue),
             viewFactory = NoOpViewFactory()
         )
     }
-
-    fun <Dependencies, Key : FragmentKey> featureFactory(
-        init: (Dependencies, Key) -> Observable<Any>
-    ): FeatureFactory<Dependencies, Key> {
-        return object : FeatureFactory<Dependencies, Key> {
-            override fun initialize(dependencies: Dependencies, key: Key): Feature<*> {
-                return Feature(
-                    state = init(dependencies, key),
-                    viewFactory = NoOpViewFactory()
-                )
-            }
-        }
-    }
 }
diff --git a/formula-android/src/test/java/com/instacart/formula/android/fakes/FakeAuthFlowFactory.kt b/formula-android/src/test/java/com/instacart/formula/android/fakes/FakeAuthFlowFactory.kt
@@ -25,7 +25,7 @@ class FakeAuthFlowFactory : FlowFactory<FakeComponent, FakeAuthFlowFactory.Compo
     }
 
     class TestFeatureFactory<FragmentKeyT : FragmentKey> : FeatureFactory<Component, FragmentKeyT> {
-        override fun initialize(dependencies: Component, key: FragmentKeyT): Feature<Any> {
+        override fun initialize(dependencies: Component, key: FragmentKeyT): Feature {
             dependencies.onInitialized(dependencies, key)
             return Feature(
                 state = Observable.empty(),

diff --git a/formula-android/src/test/java/com/instacart/formula/android/fakes/NoOpFeatureFactory.kt b/formula-android/src/test/java/com/instacart/formula/android/fakes/NoOpFeatureFactory.kt
@@ -7,7 +7,7 @@ import io.reactivex.rxjava3.core.Observable
 
 class NoOpFeatureFactory<FragmentKeyT : FragmentKey> : FeatureFactory<Unit, FragmentKeyT> {
 
-    override fun initialize(dependencies: Unit, key: FragmentKeyT): Feature<Any> {
+    override fun initialize(dependencies: Unit, key: FragmentKeyT): Feature {
         return Feature(
             state = Observable.empty(),
             viewFactory = NoOpViewFactory()

diff --git a/...-compose/src/main/java/com/instacart/formula/compose/stopwatch/StopwatchFeatureFactory.kt b/...-compose/src/main/java/com/instacart/formula/compose/stopwatch/StopwatchFeatureFactory.kt
@@ -24,7 +24,7 @@ import com.instacart.formula.invoke
 import com.instacart.formula.rxjava3.toObservable
 
 class StopwatchFeatureFactory : FeatureFactory<Any, StopwatchKey> {
-    override fun initialize(dependencies: Any, key: StopwatchKey): Feature<*> {
+    override fun initialize(dependencies: Any, key: StopwatchKey): Feature {
         return Feature(
             state = StopwatchFormula().toObservable(),
             viewFactory = StopwatchViewFactory()

diff --git a/samples/todoapp/src/main/java/com/examples/todoapp/tasks/TaskListFeatureFactory.kt b/samples/todoapp/src/main/java/com/examples/todoapp/tasks/TaskListFeatureFactory.kt
@@ -15,7 +15,7 @@ class TaskListFeatureFactory : FeatureFactory<TaskListFeatureFactory.Dependencie
         fun taskListInput(): TaskListFormula.Input
     }
 
-    override fun initialize(dependencies: Dependencies, key: TaskListKey): Feature<*> {
+    override fun initialize(dependencies: Dependencies, key: TaskListKey): Feature {
         // Note: we could create our own internal dagger component here using the dependencies.
         val formula = TaskListFormula(dependencies.taskRepo())
         return Feature(