Make TestStore.state public (#1127)

* Make TestStore.state public.

* wip

Author: mbrandonw

Sources/ComposableArchitecture/TestSupport/TestStore.swift

@@ -175,7 +175,7 @@
     private var inFlightEffects: Set<LongLivingEffect> = []
     var receivedActions: [(action: Action, state: State)] = []
     private let reducer: Reducer<State, Action, Environment>
-    private var state: State
+    public private(set) var state: State
     private var store: Store<State, TestAction>!
     private let toLocalState: (State) -> LocalState
 
@@ -352,8 +352,13 @@
         )
       }
       var expectedState = self.toLocalState(self.state)
+      let previousState = self.state
       self.store.send(.init(origin: .send(action), file: file, line: line))
       do {
+        let currentState = self.state
+        self.state = previousState
+        defer { self.state = currentState }
+
         try self.expectedStateShouldChange(
           expected: &expectedState,
           update: update,

Tests/ComposableArchitectureTests/TestStoreTests.swift

@@ -145,4 +145,43 @@ class TestStoreTests: XCTestCase {
       }
     }
   }
+
+  func testStateAccess() {
+    enum Action { case a, b, c, d }
+    let store = TestStore(
+      initialState: 0,
+      reducer: Reducer<Int, Action, Void> { count, action, _ in
+        switch action {
+        case .a:
+          count += 1
+          return .merge(.init(value: .b), .init(value: .c), .init(value: .d))
+        case .b, .c, .d:
+          count += 1
+          return .none
+        }
+      },
+      environment: ()
+    )
+
+    store.send(.a) {
+      $0 = 1
+      XCTAssertEqual(store.state, 0)
+    }
+    XCTAssertEqual(store.state, 1)
+    store.receive(.b) {
+      $0 = 2
+      XCTAssertEqual(store.state, 1)
+    }
+    XCTAssertEqual(store.state, 2)
+    store.receive(.c) {
+      $0 = 3
+      XCTAssertEqual(store.state, 2)
+    }
+    XCTAssertEqual(store.state, 3)
+    store.receive(.d) {
+      $0 = 4
+      XCTAssertEqual(store.state, 3)
+    }
+    XCTAssertEqual(store.state, 4)
+  }
 }