Added tests for producer-consumer pattern

producer-consumer/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>

producer-consumer/src/test/java/com/iluwatar/producer/consumer/ConsumerTest.java

@@ -0,0 +1,39 @@
+package com.iluwatar.producer.consumer;
+
+import org.junit.Test;
+import org.mockito.InOrder;
+
+import static org.mockito.Mockito.inOrder;
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
+
+/**
+ * Date: 12/27/15 - 11:01 PM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class ConsumerTest extends StdOutTest {
+
+  private static final int ITEM_COUNT = 5;
+
+  @Test
+  public void testConsume() throws Exception {
+    final ItemQueue queue = spy(new ItemQueue());
+    for (int id = 0; id < ITEM_COUNT; id++) {
+      queue.put(new Item("producer", id));
+    }
+
+    reset(queue); // Don't count the preparation above as interactions with the queue
+    final Consumer consumer = new Consumer("consumer", queue);
+
+    final InOrder inOrder = inOrder(getStdOutMock());
+    for (int id = 0; id < ITEM_COUNT; id++) {
+      consumer.consume();
+      inOrder.verify(getStdOutMock())
+              .println("Consumer [consumer] consume item [" + id + "] produced by [producer]");
+    }
+
+    inOrder.verifyNoMoreInteractions();
+  }
+
+}

producer-consumer/src/test/java/com/iluwatar/producer/consumer/ProducerTest.java

@@ -0,0 +1,28 @@
+package com.iluwatar.producer.consumer;
+
+import org.junit.Test;
+
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+/**
+ * Date: 12/28/15 - 12:12 AM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class ProducerTest {
+
+  @Test(timeout = 6000)
+  public void testProduce() throws Exception {
+    final ItemQueue queue = mock(ItemQueue.class);
+    final Producer producer = new Producer("producer", queue);
+
+    producer.produce();
+    verify(queue).put(any(Item.class));
+
+    verifyNoMoreInteractions(queue);
+  }
+
+}

producer-consumer/src/test/java/com/iluwatar/producer/consumer/StdOutTest.java

@@ -0,0 +1,53 @@
+package com.iluwatar.producer.consumer;
+
+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;
+  }
+
+}