Implement change manager unit tests

src/test/java/dev/kske/undoredo/ChangeManagerTest.java

@@ -1,8 +1,8 @@
 package dev.kske.undoredo;
 
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.*;
 
-import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.*;
 
 /**
  * @author Kai S. K. Engelbart
@@ -10,67 +10,95 @@ import org.junit.jupiter.api.Test;
  */
 class ChangeManagerTest {
 
+	ChangeManager<IntChange>	manager;
+	IntWrapper					wrapper;
+	IntChange					change;
+
+	@BeforeEach
+	void prepareChangeManager() {
+		manager	= new ChangeManager<>();
+		wrapper	= new IntWrapper();
+		change	= new IntChange(wrapper, 1);
+	}
+
 	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#addChange(dev.kske.undoredo.Change)}.
+	 * Tests adding a change.
+	 *
+	 * @since 0.0.1
 	 */
 	@Test
+	@Order(1)
 	void testAddChange() {
-		fail("Not yet implemented");
+		assertSame(0, wrapper.value);
+		manager.addChange(change);
+		assertSame(1, wrapper.value);
 	}
-
+	
 	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#undo()}.
-	 */
-	@Test
-	void testUndo() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#redo()}.
-	 */
-	@Test
-	void testRedo() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#mark()}.
-	 */
-	@Test
-	void testMark() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#isAtMarkedIndex()}.
-	 */
-	@Test
-	void testIsAtMarkedIndex() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#isUndoAvailable()}.
-	 */
-	@Test
-	void testIsUndoAvailable() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#isRedoAvailable()}.
-	 */
-	@Test
-	void testIsRedoAvailable() {
-		fail("Not yet implemented");
-	}
-
-	/**
-	 * Test method for {@link dev.kske.undoredo.ChangeManager#getChanges()}.
+	 * Tests the consistency of the change list.
+	 *
+	 * @since 0.0.1
 	 */
 	@Test
+	@Order(2)
 	void testGetChanges() {
-		fail("Not yet implemented");
+		assertTrue(manager.getChanges().isEmpty());
+		manager.addChange(change);
+		assertSame(1, manager.getChanges().size());
+		assertEquals(change, manager.getChanges().get(0));
+	}
+
+	/**
+	 * Test undoing a change.
+	 *
+	 * @since 0.0.1
+	 */
+	@Test
+	@Order(2)
+	void testUndo() {
+		assertFalse(manager.isUndoAvailable());
+		assertFalse(manager.undo());
+		manager.addChange(change);
+		assertTrue(manager.isUndoAvailable());
+		assertTrue(manager.undo());
+		assertFalse(manager.isUndoAvailable());
+		assertFalse(manager.undo());
+	}
+
+	/**
+	 * Tests redoing a change.
+	 *
+	 * @since 0.0.1
+	 */
+	@Test
+	@Order(4)
+	void testRedo() {
+		assertFalse(manager.isRedoAvailable());
+		assertFalse(manager.redo());
+		manager.addChange(change);
+		assertFalse(manager.isRedoAvailable());
+		assertFalse(manager.redo());
+		manager.undo();
+		assertTrue(manager.isRedoAvailable());
+		assertTrue(manager.redo());
+		assertFalse(manager.isRedoAvailable());
+		assertFalse(manager.redo());
+	}
+
+	/**
+	 * Tests marking a change.
+	 *
+	 * @since 0.0.1
+	 */
+	@Test
+	@Order(5)
+	void testMark() {
+		assertTrue(manager.isAtMarkedIndex());
+		manager.addChange(change);
+		assertFalse(manager.isAtMarkedIndex());
+		manager.mark();
+		assertTrue(manager.isAtMarkedIndex());
+		manager.undo();
+		assertFalse(manager.isAtMarkedIndex());
 	}
 }

src/test/java/dev/kske/undoredo/IntChange.java

@@ -0,0 +1,31 @@
+package dev.kske.undoredo;
+
+/**
+ * @author Kai S. K. Engelbart
+ * @since 0.0.1
+ */
+class IntChange implements Change {
+	
+	private final IntWrapper wrapper;
+	private final int value;
+	
+	IntChange(IntWrapper wrapper, int value) {
+		this.wrapper = wrapper;
+		this.value = value;
+	}
+
+	@Override
+	public void apply() {
+		wrapper.value += value;
+	}
+
+	@Override
+	public Change invert() {
+		return new IntChange(wrapper, -value);
+	}
+
+	@Override
+	public boolean isIdentity() {
+		return value == 0;
+	}
+}

src/test/java/dev/kske/undoredo/IntWrapper.java

@@ -0,0 +1,10 @@
+package dev.kske.undoredo;
+
+/**
+ * @author Kai S. K. Engelbart
+ * @since 0.0.1
+ */
+class IntWrapper {
+	
+	int value;
+}