Added tests for twin pattern

twin/pom.xml

@@ -14,5 +14,10 @@
       <artifactId>junit</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 </project>

twin/src/main/java/com/iluwatar/twin/App.java

@@ -41,6 +41,6 @@ public static void main(String[] args) throws Exception {
   }
 
   private static void waiting() throws Exception {
-    Thread.sleep(2500);
+    Thread.sleep(750);
   }
 }

twin/src/main/java/com/iluwatar/twin/BallThread.java

@@ -25,15 +25,14 @@ public void setTwin(BallItem twin) {
   public void run() {
 
     while (isRunning) {
-      while (!isSuspended) {
+      if (!isSuspended) {
         twin.draw();
         twin.move();
-        try {
-          Thread.sleep(1000);
-        } catch (InterruptedException e) {
-          throw new RuntimeException(e);
-        }
-
+      }
+      try {
+        Thread.sleep(250);
+      } catch (InterruptedException e) {
+        throw new RuntimeException(e);
       }
     }
   }

twin/src/test/java/com/iluwatar/twin/BallItemTest.java

@@ -0,0 +1,62 @@
+package com.iluwatar.twin;
+
+import org.junit.Test;
+import org.mockito.InOrder;
+
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+/**
+ * Date: 12/30/15 - 18:44 PM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class BallItemTest extends StdOutTest {
+
+  @Test
+  public void testClick() {
+    final BallThread ballThread = mock(BallThread.class);
+    final BallItem ballItem = new BallItem();
+    ballItem.setTwin(ballThread);
+
+    final InOrder inOrder = inOrder(ballThread);
+
+    for (int i = 0; i < 10; i++) {
+      ballItem.click();
+      inOrder.verify(ballThread).suspendMe();
+
+      ballItem.click();
+      inOrder.verify(ballThread).resumeMe();
+    }
+
+    inOrder.verifyNoMoreInteractions();
+  }
+
+  @Test
+  public void testDoDraw() {
+    final BallItem ballItem = new BallItem();
+    final BallThread ballThread = mock(BallThread.class);
+    ballItem.setTwin(ballThread);
+
+    ballItem.draw();
+    verify(getStdOutMock()).println("draw");
+    verify(getStdOutMock()).println("doDraw");
+
+    verifyNoMoreInteractions(ballThread, getStdOutMock());
+  }
+
+  @Test
+  public void testMove() {
+    final BallItem ballItem = new BallItem();
+    final BallThread ballThread = mock(BallThread.class);
+    ballItem.setTwin(ballThread);
+
+    ballItem.move();
+    verify(getStdOutMock()).println("move");
+
+    verifyNoMoreInteractions(ballThread, getStdOutMock());
+  }
+
+}

twin/src/test/java/com/iluwatar/twin/BallThreadTest.java

@@ -0,0 +1,89 @@
+package com.iluwatar.twin;
+
+import org.junit.Test;
+
+import static java.lang.Thread.UncaughtExceptionHandler;
+import static java.lang.Thread.sleep;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+/**
+ * Date: 12/30/15 - 18:55 PM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class BallThreadTest {
+
+  /**
+   * Verify if the {@link BallThread} can be resumed
+   */
+  @Test(timeout = 5000)
+  public void testSuspend() throws Exception {
+    final BallThread ballThread = new BallThread();
+
+    final BallItem ballItem = mock(BallItem.class);
+    ballThread.setTwin(ballItem);
+
+    ballThread.start();
+
+    verify(ballItem, timeout(2000).atLeastOnce()).draw();
+    verify(ballItem, timeout(2000).atLeastOnce()).move();
+    ballThread.suspendMe();
+
+    sleep(1000);
+
+    ballThread.stopMe();
+    ballThread.join();
+
+    verifyNoMoreInteractions(ballItem);
+  }
+
+  /**
+   * Verify if the {@link BallThread} can be resumed
+   */
+  @Test(timeout = 5000)
+  public void testResume() throws Exception {
+    final BallThread ballThread = new BallThread();
+
+    final BallItem ballItem = mock(BallItem.class);
+    ballThread.setTwin(ballItem);
+
+    ballThread.suspendMe();
+    ballThread.start();
+
+    sleep(1000);
+
+    verifyZeroInteractions(ballItem);
+
+    ballThread.resumeMe();
+    verify(ballItem, timeout(2000).atLeastOnce()).draw();
+    verify(ballItem, timeout(2000).atLeastOnce()).move();
+
+    ballThread.stopMe();
+    ballThread.join();
+
+    verifyNoMoreInteractions(ballItem);
+  }
+
+  /**
+   * Verify if the {@link BallThread} is interruptible
+   */
+  @Test(timeout = 5000)
+  public void testInterrupt() throws Exception {
+    final BallThread ballThread = new BallThread();
+    final UncaughtExceptionHandler exceptionHandler = mock(UncaughtExceptionHandler.class);
+    ballThread.setUncaughtExceptionHandler(exceptionHandler);
+    ballThread.setTwin(mock(BallItem.class));
+    ballThread.start();
+    ballThread.interrupt();
+    ballThread.join();
+
+    verify(exceptionHandler).uncaughtException(eq(ballThread), any(RuntimeException.class));
+    verifyNoMoreInteractions(exceptionHandler);
+  }
+}

twin/src/test/java/com/iluwatar/twin/StdOutTest.java

@@ -0,0 +1,53 @@
+package com.iluwatar.twin;
+
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.PrintStream;
+
+import static org.mockito.Mockito.mock;
+
+/**
+ * Date: 12/10/15 - 8:37 PM
+ *
+ * @author Jeroen Meulemeester
+ */
+public abstract class StdOutTest {
+
+  /**
+   * The mocked standard out {@link PrintStream}, required since some actions don't have any
+   * influence on accessible objects, except for writing to std-out using {@link System#out}
+   */
+  private final PrintStream stdOutMock = mock(PrintStream.class);
+
+  /**
+   * Keep the original std-out so it can be restored after the test
+   */
+  private final PrintStream stdOutOrig = System.out;
+
+  /**
+   * Inject the mocked std-out {@link PrintStream} into the {@link System} class before each test
+   */
+  @Before
+  public void setUp() {
+    System.setOut(this.stdOutMock);
+  }
+
+  /**
+   * Removed the mocked std-out {@link PrintStream} again from the {@link System} class
+   */
+  @After
+  public void tearDown() {
+    System.setOut(this.stdOutOrig);
+  }
+
+  /**
+   * Get the mocked stdOut {@link PrintStream}
+   *
+   * @return The stdOut print stream mock, renewed before each test
+   */
+  final PrintStream getStdOutMock() {
+    return this.stdOutMock;
+  }
+
+}