Allow defer in xcAwait. simplify sending state actions from a publisher. Fix tests.

RiotSwiftUI/Modules/Common/StateStore/StateStorePublisherExtensions.swift

@@ -1,26 +0,0 @@
-import Foundation
-import Combine
-
-@available(iOS 14.0, *)
-extension Publisher {
-    
-    func sinkDispatchTo<S, SA, IA>(_ store: StateStoreViewModel<S, SA, IA>) where SA == Output, Failure == Never {
-        return self
-            .subscribe(on: DispatchQueue.main)
-            .sink { [weak store] (output) in
-                guard let store = store else { return }
-                store.dispatch(action: output)
-            }
-            .store(in: &store.cancellables)
-    }
-    
-    
-    func dispatchTo<S, SA, IA>(_ store: StateStoreViewModel<S, SA, IA>)  -> Publishers.HandleEvents<Publishers.SubscribeOn<Self, DispatchQueue>> where SA == Output, Failure == Never {
-        return self
-            .subscribe(on: DispatchQueue.main)
-            .handleEvents(receiveOutput: { [weak store] action in
-                guard let store = store else { return }
-                store.dispatch(action: action)
-            })
-    }
-}

RiotSwiftUI/Modules/Common/Test/XCTestPublisherExtensions.swift

@@ -34,6 +34,25 @@ extension XCTestCase {
         _ publisher: T,
         timeout: TimeInterval = 10
     ) throws -> T.Output {
+        return try xcAwaitDeferred(publisher, timeout: timeout)()
+    }
+    
+    /// XCTest utility that allows for a deferred wait of results from publishers, so that the output can be used for assertions.
+    ///
+    ///  ```
+    /// let collectedEvents = somePublisher.collect(3).first()
+    /// let awaitDeferred = xcAwaitDeferred(collectedEvents)
+    /// // Do some other work that publishes to somePublisher
+    /// XCTAssertEqual(try awaitDeferred(), [expected, values, here])
+    ///  ```
+    /// - Parameters:
+    ///   - publisher: The publisher to wait on.
+    ///   - timeout: A timeout after which we give up.
+    /// - Returns: A closure that starts the waiting of results when called. The closure will return the unwrapped result.
+    func xcAwaitDeferred<T: Publisher>(
+        _ publisher: T,
+        timeout: TimeInterval = 10
+    ) -> (() throws -> (T.Output)) {
         var result: Result<T.Output, Error>?
         let expectation = self.expectation(description: "Awaiting publisher")
 
@@ -52,12 +71,14 @@ extension XCTestCase {
                 result = .success(value)
             }
         )
-        waitForExpectations(timeout: timeout)
-        cancellable.cancel()
-        let unwrappedResult = try XCTUnwrap(
-            result,
-            "Awaited publisher did not produce any output"
-        )
-        return try unwrappedResult.get()
+        return {
+            self.waitForExpectations(timeout: timeout)
+            cancellable.cancel()
+            let unwrappedResult = try XCTUnwrap(
+                result,
+                "Awaited publisher did not produce any output"
+            )
+            return try unwrappedResult.get()
+        }
     }
 }

RiotSwiftUI/Modules/Common/ViewModel/StateStoreViewModel.swift

@@ -72,13 +72,13 @@ class ViewModelContext<ViewState:BindableState, ViewAction>: ObservableObject {
     }
 }
 
-@available(iOS 14, *)
 /// A common ViewModel implementation for handling of `State`, `StateAction`s and `ViewAction`s
 ///
 /// Generic type State is constrained to the BindableState protocol in that it may contain (but doesn't have to)
 /// a specific portion of state that can be safely bound to.
 /// If we decide to add more features to our state management (like doing state processing off the main thread)
 /// we can do it in this centralised place.
+@available(iOS 14, *)
 class StateStoreViewModel<State: BindableState, StateAction, ViewAction> {
     
     typealias Context = ViewModelContext<State, ViewAction>
@@ -105,7 +105,8 @@ class StateStoreViewModel<State: BindableState, StateAction, ViewAction> {
         self.context = Context(initialViewState: initialViewState)
         self.state = CurrentValueSubject(initialViewState)
         // Connect the state to context viewState, that view uses for observing (but not modifying directly) the state.
-        self.state.weakAssign(to: \.context.viewState, on: self)
+        self.state
+            .weakAssign(to: \.context.viewState, on: self)
             .store(in: &cancellables)
         // Receive events from the view and pass on to the `ViewModel` for processing.
         self.context.viewActions.sink { [weak self] action in
@@ -120,6 +121,16 @@ class StateStoreViewModel<State: BindableState, StateAction, ViewAction> {
     func dispatch(action: StateAction) {
         Self.reducer(state: &state.value, action: action)
     }
+    
+    /// Send state actions from a publisher to modify the state within the reducer.
+    /// - Parameter actionPublisher: The publisher that produces actions to be sent to the reducer
+    func dispatch(actionPublisher: AnyPublisher<StateAction, Never>) {
+        actionPublisher.sink { [weak self] action in
+            guard let self = self else { return }
+            Self.reducer(state: &self.state.value, action: action)
+        }
+        .store(in: &cancellables)
+    }
 
     /// Override to handle mutations to the `State`
     ///

RiotSwiftUI/Modules/Template/SimpleUserProfileExample/Service/Mock/MockTemplateUserProfileService.swift

@@ -37,6 +37,6 @@ class MockTemplateUserProfileService: TemplateUserProfileServiceProtocol {
     }
     
     func simulateUpdate(presence: TemplateUserProfilePresence) {
-        self.presenceSubject.send(presence)
+        self.presenceSubject.value = presence
     }
 }

RiotSwiftUI/Modules/Template/SimpleUserProfileExample/Test/Unit/TemplateUserProfileViewModelTests.swift

@@ -26,29 +26,32 @@ class TemplateUserProfileViewModelTests: XCTestCase {
         static let displayName = "Alice"
     }
     var service: MockTemplateUserProfileService!
-    var viewModel: TemplateUserProfileViewModel!
+    var viewModel: TemplateUserProfileViewModelProtocol!
+    var context: TemplateUserProfileViewModelType.Context!
     var cancellables = Set<AnyCancellable>()
     override func setUpWithError() throws {
         service = MockTemplateUserProfileService(displayName: Constants.displayName, presence: Constants.presenceInitialValue)
-        viewModel = TemplateUserProfileViewModel(templateUserProfileService: service)
+        viewModel = TemplateUserProfileViewModel.makeTemplateUserProfileViewModel(templateUserProfileService: service)
+        context = viewModel.context
     }
     
     func testInitialState() {
-        XCTAssertEqual(viewModel.viewState.displayName, Constants.displayName)
-        XCTAssertEqual(viewModel.viewState.presence, Constants.presenceInitialValue)
+        XCTAssertEqual(context.viewState.displayName, Constants.displayName)
+        XCTAssertEqual(context.viewState.presence, Constants.presenceInitialValue)
     }
 
     func testFirstPresenceReceived() throws {
-        let presencePublisher = viewModel.$viewState.map(\.presence).removeDuplicates().collect(1).first()
+        let presencePublisher = context.$viewState.map(\.presence).removeDuplicates().collect(1).first()
         XCTAssertEqual(try xcAwait(presencePublisher), [Constants.presenceInitialValue])
     }
     
     func testPresenceUpdatesReceived() throws {
-        let presencePublisher = viewModel.$viewState.map(\.presence).removeDuplicates().collect(3).first()
+        let presencePublisher = context.$viewState.map(\.presence).removeDuplicates().collect(3).first()
+        let awaitDeferred = xcAwaitDeferred(presencePublisher)
         let newPresenceValue1: TemplateUserProfilePresence = .online
         let newPresenceValue2: TemplateUserProfilePresence = .idle
         service.simulateUpdate(presence: newPresenceValue1)
         service.simulateUpdate(presence: newPresenceValue2)
-        XCTAssertEqual(try xcAwait(presencePublisher), [Constants.presenceInitialValue, newPresenceValue1, newPresenceValue2])
+        XCTAssertEqual(try awaitDeferred(), [Constants.presenceInitialValue, newPresenceValue1, newPresenceValue2])
     }
 }

RiotSwiftUI/Modules/Template/SimpleUserProfileExample/ViewModel/TemplateUserProfileViewModel.swift

@@ -57,9 +57,10 @@ class TemplateUserProfileViewModel: TemplateUserProfileViewModelType, TemplateUs
     }
     
     private func setupPresenceObserving() {
-        templateUserProfileService.presenceSubject
+        let presenceUpdatePublisher = templateUserProfileService.presenceSubject
             .map(TemplateUserProfileStateAction.updatePresence)
-            .sinkDispatchTo(self)
+            .eraseToAnyPublisher()
+        dispatch(actionPublisher: presenceUpdatePublisher)
     }
     
     // MARK: - Public