Added tests for object-pool pattern

object-pool/src/test/java/com/iluwatar/object/pool/OliphauntPoolTest.java

@@ -0,0 +1,99 @@
+package com.iluwatar.object.pool;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotSame;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Date: 12/27/15 - 1:05 AM
+ *
+ * @author Jeroen Meulemeester
+ */
+public class OliphauntPoolTest {
+
+  /**
+   * Use the same object 100 times subsequently. This should not take much time since the heavy
+   * object instantiation is done only once. Verify if we get the same object each time.
+   */
+  @Test(timeout = 5000)
+  public void testSubsequentCheckinCheckout() {
+    final OliphauntPool pool = new OliphauntPool();
+    assertEquals(pool.toString(), "Pool available=0 inUse=0");
+
+    final Oliphaunt expectedOliphaunt = pool.checkOut();
+    assertEquals(pool.toString(), "Pool available=0 inUse=1");
+
+    pool.checkIn(expectedOliphaunt);
+    assertEquals(pool.toString(), "Pool available=1 inUse=0");
+
+    for (int i = 0; i < 100; i++) {
+      final Oliphaunt oliphaunt = pool.checkOut();
+      assertEquals(pool.toString(), "Pool available=0 inUse=1");
+      assertSame(expectedOliphaunt, oliphaunt);
+      assertEquals(expectedOliphaunt.getId(), oliphaunt.getId());
+      assertEquals(expectedOliphaunt.toString(), oliphaunt.toString());
+
+      pool.checkIn(oliphaunt);
+      assertEquals(pool.toString(), "Pool available=1 inUse=0");
+    }
+
+  }
+
+  /**
+   * Use the same object 100 times subsequently. This should not take much time since the heavy
+   * object instantiation is done only once. Verify if we get the same object each time.
+   */
+  @Test(timeout = 5000)
+  public void testConcurrentCheckinCheckout() {
+    final OliphauntPool pool = new OliphauntPool();
+    assertEquals(pool.toString(), "Pool available=0 inUse=0");
+
+    final Oliphaunt firstOliphaunt = pool.checkOut();
+    assertEquals(pool.toString(), "Pool available=0 inUse=1");
+
+    final Oliphaunt secondOliphaunt = pool.checkOut();
+    assertEquals(pool.toString(), "Pool available=0 inUse=2");
+
+    assertNotSame(firstOliphaunt, secondOliphaunt);
+    assertEquals(firstOliphaunt.getId() + 1, secondOliphaunt.getId());
+
+    // After checking in the second, we should get the same when checking out a new oliphaunt ...
+    pool.checkIn(secondOliphaunt);
+    assertEquals(pool.toString(), "Pool available=1 inUse=1");
+
+    final Oliphaunt oliphaunt3 = pool.checkOut();
+    assertEquals(pool.toString(), "Pool available=0 inUse=2");
+    assertSame(secondOliphaunt, oliphaunt3);
+
+    // ... and the same applies for the first one
+    pool.checkIn(firstOliphaunt);
+    assertEquals(pool.toString(), "Pool available=1 inUse=1");
+
+    final Oliphaunt oliphaunt4 = pool.checkOut();
+    assertEquals(pool.toString(), "Pool available=0 inUse=2");
+    assertSame(firstOliphaunt, oliphaunt4);
+
+    // When both oliphaunt return to the pool, we should still get the same instances
+    pool.checkIn(firstOliphaunt);
+    assertEquals(pool.toString(), "Pool available=1 inUse=1");
+
+    pool.checkIn(secondOliphaunt);
+    assertEquals(pool.toString(), "Pool available=2 inUse=0");
+
+    // The order of the returned instances is not determined, so just put them in a list
+    // and verify if both expected instances are in there.
+    final List<Oliphaunt> oliphaunts = Arrays.asList(pool.checkOut(), pool.checkOut());
+    assertEquals(pool.toString(), "Pool available=0 inUse=2");
+    assertTrue(oliphaunts.contains(firstOliphaunt));
+    assertTrue(oliphaunts.contains(secondOliphaunt));
+
+  }
+
+
+}