Loesung der Aufgabe

src/main/java/de/edu/hsfulda/ccip/tdd/withdependencies/GameOfLifeCell.java

@@ -9,9 +9,13 @@ public class GameOfLifeCell {
 	private GameOfLifeStatus status;
 	private final Collection<GameOfLifeCell> neighborStates = new LinkedList<>();
 	private GameOfLifeStatus nexState;
+	private GameOfLifeStateChangeListener stateChangeListener;
 
-	public GameOfLifeCell(GameOfLifeStatus status) {
+	public GameOfLifeCell(//
+			GameOfLifeStatus status, //
+			GameOfLifeStateChangeListener stateChangeListener) {
 		this.status = status;
+		this.stateChangeListener = stateChangeListener;
 	}
 
 	public void addNeighbor(GameOfLifeCell neighbor) {
@@ -21,6 +25,8 @@ public class GameOfLifeCell {
 	public void caclulateNextState() {
 		nexState = status
 				.calculateNextBy(neighborStates.stream().map(GameOfLifeCell::getState).collect(Collectors.toList()));
+		if (!nexState.equals(status))
+			stateChangeListener.stateChangedIn(this);
 	}
 
 	public GameOfLifeStatus getState() {

src/main/java/de/edu/hsfulda/ccip/tdd/withdependencies/GameOfLifeStateChangeListener.java

@@ -0,0 +1,7 @@
+package de.edu.hsfulda.ccip.tdd.withdependencies;
+
+public interface GameOfLifeStateChangeListener {
+
+	void stateChangedIn(GameOfLifeCell gameOfLifeCell);
+
+}

src/test/java/de/edu/hsfulda/ccip/tdd/withdependencies/GameOfLifeCellTest.java

@@ -1,6 +1,7 @@
 package de.edu.hsfulda.ccip.tdd.withdependencies;
 
 import static org.junit.Assert.assertThat;
+import static org.junit.jupiter.api.Assertions.*;
 
 import java.util.Arrays;
 import java.util.Collections;
@@ -15,16 +16,20 @@ import org.mockito.Mockito;
 
 class GameOfLifeCellTest {
 
+	private GameOfLifeStateChangeListener stateChangeListener =
+			Mockito.mock(GameOfLifeStateChangeListener.class);
+	
 	private GameOfLifeStatus status = Mockito.mock(GameOfLifeStatus.class, "initial state");
 
 	private GameOfLifeCell gameOfLifeCell;
 
 	private List<GameOfLifeCell> neighbors;
-	private GameOfLifeCell neigborCell = Mockito.mock(GameOfLifeCell.class);
+	private GameOfLifeCell neigborCell = Mockito.mock(GameOfLifeCell.class,"neighbor");
 
 	@BeforeEach
 	void setUp() throws Exception {
-		gameOfLifeCell = new GameOfLifeCell(status);
+		Mockito.doReturn(status).when(status).calculateNextBy(Mockito.anyList());
+		gameOfLifeCell = new GameOfLifeCell(status,stateChangeListener);
 		neighbors = Arrays.asList(neigborCell, neigborCell, neigborCell, neigborCell, neigborCell, neigborCell,
 				neigborCell, neigborCell);
 
@@ -73,4 +78,28 @@ class GameOfLifeCellTest {
 		assertThat("status  changed", currentState, CoreMatchers.equalTo(newState));
 	}
 	
+	@Test
+	void callsChangeListenerWhenStateChanges() throws Exception {
+		GameOfLifeStatus newState = Mockito.mock(GameOfLifeStatus.class, "new state");
+		Mockito
+		.doReturn(newState)
+		.when(status)
+		.calculateNextBy(Mockito.anyList());
+
+		gameOfLifeCell.caclulateNextState();
+		
+		Mockito.verify(stateChangeListener).stateChangedIn(gameOfLifeCell);
+	}
+
+	@Test
+	void doesNotCallsChangeListenerWhenStateNotChanges() throws Exception {
+		Mockito.doReturn(status)
+		.when(status).calculateNextBy(Mockito.anyList());
+
+		
+		gameOfLifeCell.caclulateNextState();
+		
+		Mockito.verify(stateChangeListener,Mockito.never()).stateChangedIn(gameOfLifeCell);
+	
+	}
 }