Add DeleteTaskCommand test cases

src/test/java/seedu/address/logic/commands/task/DeleteTaskCommandTest.java

@@ -0,0 +1,61 @@
+package seedu.address.logic.commands.task;
+
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandFailure;
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandSuccess;
+import static seedu.address.testutil.TypicalPersons.getTypicalAddressBook;
+import static seedu.address.testutil.TypicalTasks.getTypicalTaskList;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.commons.core.Messages;
+import seedu.address.commons.core.index.Index;
+import seedu.address.model.Model;
+import seedu.address.model.ModelManager;
+import seedu.address.model.UserPrefs;
+import seedu.address.model.tag.Tag;
+import seedu.address.model.task.Task;
+import seedu.address.model.task.filters.TaskFilters;
+
+public class DeleteTaskCommandTest {
+    private Model model = new ModelManager(getTypicalAddressBook(), getTypicalTaskList(), new UserPrefs());
+
+    @Test
+    public void execute_validIndexUnfilteredList_success() {
+        Index targetIndex = Index.fromOneBased(1);
+        Task taskToDelete = model.getFilteredTaskList().get(targetIndex.getZeroBased());
+        DeleteTaskCommand deleteTaskCommand = new DeleteTaskCommand(targetIndex);
+        String expectedMessage = String.format(DeleteTaskCommand.MESSAGE_SUCCESS, taskToDelete);
+        ModelManager expectedModel = ModelManager.from(model);
+        expectedModel.deleteTask(taskToDelete);
+        assertCommandSuccess(deleteTaskCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_invalidIndexUnfilteredList_throwsCommandException() {
+        Index outOfBoundIndex = Index.fromOneBased(model.getFilteredTaskList().size() + 1);
+        DeleteTaskCommand deleteTaskCommand = new DeleteTaskCommand(outOfBoundIndex);
+        assertCommandFailure(deleteTaskCommand, model, Messages.MESSAGE_INVALID_TASK_DISPLAYED_INDEX);
+    }
+
+    @Test
+    public void execute_validIndexFilteredList_success() {
+        model.addTaskFilter(TaskFilters.FILTER_TAG.apply(new Tag("homework")));
+        Index targetIndex = Index.fromOneBased(1);
+        Task taskToDelete = model.getFilteredTaskList().get(targetIndex.getZeroBased());
+        DeleteTaskCommand deleteTaskCommand = new DeleteTaskCommand(targetIndex);
+        String expectedMessage = String.format(DeleteTaskCommand.MESSAGE_SUCCESS, taskToDelete);
+        ModelManager expectedModel = ModelManager.from(model);
+        expectedModel.deleteTask(taskToDelete);
+        assertCommandSuccess(deleteTaskCommand, model, expectedMessage, expectedModel);
+
+    }
+    @Test
+    public void execute_invalidIndexFilteredList_throwsCommandException() {
+        model.addTaskFilter(TaskFilters.FILTER_TAG.apply(new Tag("homework")));
+        Index targetIndex = Index.fromOneBased(2);
+        DeleteTaskCommand deleteTaskCommand = new DeleteTaskCommand(targetIndex);
+        assertCommandFailure(deleteTaskCommand, model, Messages.MESSAGE_INVALID_TASK_DISPLAYED_INDEX);
+
+    }
+
+}