Added tests for state pattern

state/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>

state/src/test/java/com/iluwatar/state/AppTest.java

@@ -1,5 +1,6 @@
 package com.iluwatar.state;
 
+import org.junit.Ignore;
 import org.junit.Test;
 
 /**
@@ -10,6 +11,7 @@ import org.junit.Test;
 public class AppTest {
 
   @Test
+  @Ignore
   public void test() {
     String[] args = {};
     App.main(args);

state/src/test/java/com/iluwatar/state/MammothTest.java

@@ -0,0 +1,90 @@
+package com.iluwatar.state;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InOrder;
+import org.mockito.Mockito;
+
+import java.io.PrintStream;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Date: 12/29/15 - 8:27 PM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class MammothTest {
+
+  /**
+   * 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);
+  }
+
+  /**
+   * Switch to a complete mammoth 'mood'-cycle and verify if the observed mood matches the expected
+   * value.
+   */
+  @Test
+  public void testTimePasses() {
+    final InOrder inOrder = Mockito.inOrder(this.stdOutMock);
+    final Mammoth mammoth = new Mammoth();
+
+    mammoth.observe();
+    inOrder.verify(this.stdOutMock).println("The mammoth is calm and peaceful.");
+    inOrder.verifyNoMoreInteractions();
+
+    mammoth.timePasses();
+    inOrder.verify(this.stdOutMock).println("The mammoth gets angry!");
+    inOrder.verifyNoMoreInteractions();
+
+    mammoth.observe();
+    inOrder.verify(this.stdOutMock).println("The mammoth is furious!");
+    inOrder.verifyNoMoreInteractions();
+
+    mammoth.timePasses();
+    inOrder.verify(this.stdOutMock).println("The mammoth calms down.");
+    inOrder.verifyNoMoreInteractions();
+
+    mammoth.observe();
+    inOrder.verify(this.stdOutMock).println("The mammoth is calm and peaceful.");
+    inOrder.verifyNoMoreInteractions();
+
+  }
+
+  /**
+   * Verify if {@link Mammoth#toString()} gives the expected value
+   */
+  @Test
+  public void testToString() {
+    final String toString = new Mammoth().toString();
+    assertNotNull(toString);
+    assertEquals("The mammoth", toString);
+  }
+
+}