Initial actions

Sources/ComposableArchitecture/Store.swift

@@ -159,11 +159,13 @@ public final class Store<State, Action> {
   ///
   /// - Parameters:
   ///   - initialState: The state to start the application in.
+  ///   - initialAction: An action to send the store when it is created.
   ///   - reducer: The reducer that powers the business logic of the application.
   ///   - prepareDependencies: A closure that can be used to override dependencies that will be accessed
   ///     by the reducer.
   public convenience init<R: Reducer<State, Action>>(
     initialState: @autoclosure () -> R.State,
+    initialAction: @autoclosure () -> R.Action? = nil,
     @ReducerBuilder<State, Action> reducer: () -> R,
     withDependencies prepareDependencies: ((inout DependencyValues) -> Void)? = nil
   ) {
@@ -175,6 +177,9 @@ public final class Store<State, Action> {
       initialState: initialState,
       reducer: reducer.dependency(\.self, dependencies)
     )
+    if let initialAction = initialAction() {
+      send(initialAction)
+    }
   }
 
   init() {

Tests/ComposableArchitectureTests/StoreTests.swift

@@ -846,7 +846,7 @@
     childTask.cancel()
     await mainQueue.advance(by: 1)
     try await Task.sleep(nanoseconds: 100_000_000)
     XCTTODO(
       """
       This fails because cancelling a child task will cancel all parent effects too.
       """
@@ -1177,7 +1177,7 @@
 
   @MainActor
   func testSharedMutation() async {
     XCTTODO(
       """
       Ideally this will pass in 2.0 but it's a breaking change for test stores to not eagerly \
       process all received actions.
@@ -1213,6 +1213,17 @@
       }
     }
   }
+
+  @MainActor
+  func testInitialAction() async {
+    let store = Store(initialState: 0, initialAction: ()) {
+      Reduce { state, _ in
+        state += 1
+        return .none
+      }
+    }
+    XCTAssertEqual(store.currentState, 1)
+  }
 }
 
 #if canImport(Testing)