added more example

core-java/src/test/java/com/baeldung/generics/GenericsTest.java

@@ -1,4 +1,8 @@
-import java.util.Iterator;
+import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.Test;
@@ -7,40 +11,45 @@ public class GenericsTest {
 
 	// testing the generic method with Integer
 	@Test
-	public void fromArrayToListIntTest() {
+	public void givenArrayOfIntegers_thanListOfIntegersReturnedOK() {
 		Integer[] intArray = { 1, 2, 3, 4, 5 };
 		List<Integer> list = Generics.fromArrayToList(intArray);
-		Iterator<Integer> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
+
+		assertThat(list, hasItems(intArray));
 	}
 
 	// testing the generic method with String
 	@Test
-	public void fromArrayToListStringTest() {
+	public void givenArrayOfStrings_thanListOfStringsReturnedOK() {
 		String[] stringArray = { "hello1", "hello2", "hello3", "hello4", "hello5" };
 		List<String> list = Generics.fromArrayToList(stringArray);
-		Iterator<String> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
+
+		assertThat(list, hasItems(stringArray));
 	}
 
 	// testing the generic method with Number as upper bound with Integer
 	// if we test fromArrayToListWithUpperBound with any type that doesn't
 	// extend Number it will fail to compile
 	@Test
-	public void fromArrayToListUpperboundIntTest() {
+	public void givenArrayOfIntegersAndNumberUpperBound_thanListOfIntegersReturnedOK() {
 		Integer[] intArray = { 1, 2, 3, 4, 5 };
 		List<Integer> list = Generics.fromArrayToListWithUpperBound(intArray);
-		Iterator<Integer> iterator;
-		iterator = list.iterator();
-		while (iterator.hasNext()) {
-			System.out.println(iterator.next());
-		}
+
+		assertThat(list, hasItems(intArray));
 	}
 
-}
+	// testing paintAllBuildings method with a subtype of Building, the method
+	// will work with all subtypes of Building
+	@Test
+	public void givenSubTypeOfAwildCardBoundedGenericMethod() {
+
+		List<SubBuilding> subBuildingsList = new ArrayList<>();
+		subBuildingsList.add(new SubBuilding());
+		subBuildingsList.add(new SubBuilding());
+
+		boolean result = Generics.paintAllBuildings(subBuildingsList);
+		assertTrue(result);
+
+	}
+
+}