Add oving 7

src/test/java/oving7/observablelist/ObservableListTest.java

@@ -0,0 +1,106 @@
+package oving7.observablelist;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+public class ObservableListTest {
+
+	private int pos1;
+	private int pos2;
+	private ObservableList observableList;
+
+	private static void checkObservableList(ObservableList list, List<Integer> elements,
+			String contextMessage) {
+		assertEquals(elements.size(), list.size(),
+				contextMessage + " -> Testing the length of observableList");
+
+		int i = 0;
+
+		for (int element : elements) {
+			assertEquals(element, list.getElement(i),
+					contextMessage + " -> Testing that the element at position " + i + " matches");
+
+			i++;
+		}
+	}
+
+	private void addElementWithListener(int pos, int element) {
+		pos1 = pos;
+		observableList.addElement(pos, element);
+
+		// Check that the position that was changed is the same as the one sent to the listener
+		assertEquals(pos1, pos2, "Added " + element + " at position " + pos
+				+ " -> Testing the position received by the listener");
+	}
+
+	@BeforeEach
+	public void setUp() {
+		observableList = new ObservableList() {
+			@Override
+			public boolean acceptsElement(Object element) {
+				return element instanceof Integer;
+			}
+		};
+		pos1 = -1;
+		pos2 = -1;
+	}
+
+	@Test
+	@DisplayName("Test constructor")
+	public void testConstructor() {
+		assertEquals(0, observableList.size());
+	}
+
+	@Test
+	@DisplayName("Test acceptance of elements")
+	public void testAcceptsElement() {
+		assertTrue(observableList.acceptsElement(5), "Testing that the list accepts integers");
+		assertFalse(observableList.acceptsElement("5"),
+				"Testing that the list does not accept strings");
+
+		assertThrows(IllegalArgumentException.class, () -> {
+			observableList.addElement("5");
+		}, "Testing that the list cannot accept elements of type string");
+	}
+
+	@Test
+	@DisplayName("Test adding elements")
+	public void testAddElement() {
+		observableList.addElement(5);
+		ObservableListTest.checkObservableList(observableList, List.of(5),
+				"Added 5 to an empty list");
+
+		observableList.addElement(6);
+		ObservableListTest.checkObservableList(observableList, List.of(5, 6),
+				"Added 6 to the list [5]");
+
+		observableList.addElement(0, 2);
+		ObservableListTest.checkObservableList(observableList, List.of(2, 5, 6),
+				"Added 2 at position 0 in the list [5, 6]");
+	}
+
+	@Test
+	@DisplayName("Test listener")
+	public void testListListener() {
+		ObservableListListener listener = (list, pos) -> pos2 = pos;
+		observableList.addObservableListListener(listener);
+
+		this.addElementWithListener(0, 5);
+		ObservableListTest.checkObservableList(observableList, List.of(5),
+				"Added 5 to the list []");
+
+		this.addElementWithListener(1, 6);
+		ObservableListTest.checkObservableList(observableList, List.of(5, 6),
+				"Added 6 to the list [5]");
+
+		this.addElementWithListener(0, 2);
+		ObservableListTest.checkObservableList(observableList, List.of(2, 5, 6),
+				"Added 2 to the list [5, 6]");
+	}
+}