Change return type of execute method of Command

src/main/java/AddCommand.java

@@ -1,3 +1,4 @@
+import java.util.ArrayList;
 import java.util.Date;
 
 /**
@@ -31,7 +32,7 @@ public AddCommand(TaskType taskType, String description, Date date) {
      * @throws DukeException
      */
     @Override
-    public String execute(TaskList tasks, Storage storage) throws DukeException {
+    public ArrayList<String> execute(TaskList tasks, Storage storage) throws DukeException {
         Task task = null;
         if (taskType == TaskType.TODO) {
             task = new ToDo(description, false);

src/main/java/Command.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 /**
  * A Command is a parsed request from the user.
  */
@@ -10,7 +12,7 @@ public abstract class Command {
      * @param storage Storage to be activated if there are any changes to TaskList.
      * @throws DukeException
      */
-    public abstract String execute(TaskList tasks, Storage storage) throws DukeException, TaskException;
+    public abstract ArrayList<String> execute(TaskList tasks, Storage storage) throws DukeException, TaskException;
 
     /**
      * Returns false for all commands except ExitCommand.

src/main/java/DeleteCommand.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 /**
  * DeleteCommand is a request to delete a Task.
  */
@@ -16,9 +18,10 @@ public DeleteCommand(int idx) {
      * @param tasks   TaskList to be modified.
      * @param storage Storage to be updated.
      * @throws DukeException
+     * @return ArrayList containing response message from Duke.
      */
     @Override
-    public String execute(TaskList tasks, Storage storage) throws DukeException {
+    public ArrayList<String> execute(TaskList tasks, Storage storage) throws DukeException {
         storage.saveList(tasks);
         return Ui.getDeletedTask(tasks.removeTask(idx), tasks);
     }

src/main/java/DoneCommand.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 /**
  * DoneCommand is a request to mark a Task as done.
  */
@@ -16,9 +18,10 @@ public DoneCommand(int idx) {
      * @param tasks   TaskList to be modified.
      * @param storage Storage to be updated.
      * @throws DukeException
+     * @return ArrayList containing response message from Duke.
      */
     @Override
-    public String execute(TaskList tasks, Storage storage) throws DukeException, TaskException {
+    public ArrayList<String> execute(TaskList tasks, Storage storage) throws DukeException, TaskException {
         tasks.markAsDone(idx);
         storage.saveList(tasks);
         return Ui.getDoneTask(tasks.getTask(idx));

src/main/java/Duke.java

@@ -30,7 +30,7 @@ public Duke(String filePath) {
     public String getResponse(String text) {
         try {
             Command c = Parser.parse(text);
-            return c.execute(tasks, storage);
+            return Ui.formatMultiLine(c.execute(tasks, storage));
         } catch (DukeException | TaskException e) {
             return e.getMessage();
         }

src/main/java/ExitCommand.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 /**
  * DeleteCommand is a request to stop Duke from running.
  */
@@ -9,9 +11,10 @@ public class ExitCommand extends Command {
      *
      * @param tasks   TaskList to be modified.
      * @param storage Storage to be activated if there are any changes to TaskList.
+     * @return ArrayList containing response message from Duke.
      */
     @Override
-    public String execute(TaskList tasks, Storage storage) {
+    public ArrayList<String> execute(TaskList tasks, Storage storage) {
         return Ui.getGoodbye();
     }
 

src/main/java/ListCommand.java

@@ -1,3 +1,4 @@
+import java.util.ArrayList;
 import java.util.Date;
 
 /**
@@ -25,10 +26,10 @@ public ListCommand(Date on, String keyWord) {
      *
      * @param tasks   TaskList to be printed.
      * @param storage Storage is not activated.
+     * @return ArrayList containing response message from Duke.
      */
     @Override
-    public String execute(TaskList tasks, Storage storage) {
+    public ArrayList<String> execute(TaskList tasks, Storage storage) {
         return Ui.getTaskList(tasks, on, keyWord);
-//        ui.showTaskList(tasks, on, keyWord);
     }
 }

src/main/java/MainWindow.java

@@ -28,7 +28,7 @@ public class MainWindow extends AnchorPane {
     @FXML
     public void initialize() {
         scrollPane.vvalueProperty().bind(dialogContainer.heightProperty());
-        DialogBox dialogBox = DialogBox.getUserDialog(Ui.getWelcome(), dukeImage);
+        DialogBox dialogBox = DialogBox.getUserDialog(Ui.formatMultiLine(Ui.getWelcome()), dukeImage);
         dialogBox.flip();
         dialogContainer.getChildren().add(dialogBox);
     }
@@ -50,7 +50,7 @@ private void handleUserInput() {
                 DialogBox.getDukeDialog(response, dukeImage)
         );
         userInput.clear();
-        if (response.equals(Ui.getGoodbye())) {
+        if (response.equals(Ui.formatMultiLine(Ui.getGoodbye()))) {
             Platform.exit();
         }
     }

src/main/java/Parser.java

@@ -81,7 +81,7 @@ public static Command parse(String userInput) throws DukeException, TaskExceptio
                 int idx = userInput.indexOf(" /by ");
                 if (idx == -1 || userInput.substring(idx + 5).isBlank()) {
                     throw new TaskException(TaskType.DEADLINE, "time", TaskExceptionType.IDENTIFY);
-                } else if (userInput.substring(9, idx).isBlank()) {
+                } else if (idx <= 9 || userInput.substring(9, idx).isBlank()) {
                     throw new TaskException(TaskType.DEADLINE, "description", TaskExceptionType.EMPTY);
                 } else {
                     if (parseDate(userInput.substring(idx + 5)) == null) {

src/main/java/Ui.java

@@ -11,7 +11,8 @@ public class Ui {
     private static final String LINE = "____________________________________________________________";
     private static final ArrayList<String> WELCOME_MSG = new ArrayList<>(Arrays.asList("Hello! I'm Duke", "What can I"
             + " do for you?"));
-    private static final String GOODBYE_MSG = "Bye. Hope to see you again soon!";
+    private static final ArrayList<String> GOODBYE_MSG = new ArrayList<>(Arrays.asList("Bye. Hope to see you again " +
+            "soon!"));
     private static final String DONE_MSG = "Nice! I've marked this task as done:";
     private static final String DELETED_MSG = "Noted. I've removed this task:";
     private static final String ADD_MSG = "Got it. I've added this task:";
@@ -27,67 +28,59 @@ public static String formatDate(Date date) {
      * @return String of formatted responses.
      */
     public static String formatResponse(ArrayList<String> response) {
-        String indentLine = LINE + "\n";
+        String indentLine = INDENT + LINE + "\n";
         String result = indentLine;
         for (String resp : response) {
-            result += resp + "\n";
+            result += INDENT + INDENT + resp + "\n";
         }
         result += indentLine;
         return result;
     }
 
     /**
      * Formats each feedback message, e.g. enclosed in two lines.
-     * Overloaded formatResponse, takes in a variable number of strings, puts them in a ArrayList and passes it to the
-     * other formatResponse method.
      *
-     * @param response Variable number of Strings of feedback messages.
+     * @param response ArrayList of feedback messages.
      * @return String of formatted responses.
      */
-    public static String formatResponse(String ... response) {
-        ArrayList<String> lst = new ArrayList<>();
-        for (String resp : response) {
-            lst.add(resp);
-        }
-        return formatResponse(lst);
-    }
-
-    public static String formatMultilineResponse(String ... response) {
-        ArrayList<String> lst = new ArrayList<>();
-        for (String resp : response) {
-            lst.add(resp);
-        }
-        return formatMultilineResponse(lst);
+    public static String formatResponse(String response) {
+        return formatResponse(new ArrayList<>(Arrays.asList(response)));
     }
 
-    public static String formatMultilineResponse(ArrayList<String> response) {
+    /**
+     * Formats each feedback message.
+     *
+     * @param response ArrayList of feedback messages.
+     * @return String of formatted responses.
+     */
+    public static String formatMultiLine(ArrayList<String> response) {
         String result = "";
         for (String resp : response) {
-            result += INDENT + resp + "\n";
+            result += resp + "\n";
         }
         return result;
     }
 
     /**
      * Returns formatted welcome message.
      *
-     * @return String Formatted welcome message.
+     * @return ArrayList welcome message.
      */
-    public static String getWelcome() {
-        return formatMultilineResponse(WELCOME_MSG);
+    public static ArrayList<String> getWelcome() {
+        return WELCOME_MSG;
     }
 
     /**
      * Returns formatted goodbye message.
      *
-     * @return String Formatted goodbye message.
+     * @return String goodbye message.
      */
-    public static String getGoodbye() {
-        return INDENT + GOODBYE_MSG;
+    public static ArrayList<String> getGoodbye() {
+        return GOODBYE_MSG;
     }
 
     /**
-     * Returns a String with count of tasks.
+     * Returns a ArrayList String with count of tasks.
      *
      * @param tasks TaskList to count number of tasks from.
      * @return String with count of tasks.
@@ -97,50 +90,61 @@ public static String getListCount(TaskList tasks) {
     }
 
     /**
-     * Returns a String containing details of all the tasks that pass date and keyWord criteria.
+     * Returns a ArrayList String containing details of all the tasks that pass date and keyWord criteria.
      *
      * @param tasks   Tasks to filter from.
      * @param date    Date to filter tasks by.
      * @param keyWord Keyword to filter tasks by.
-     * @return String containing details of tasks that fulfil the criteria.
+     * @return ArrayList containing details of tasks that fulfil the criteria.
      */
-    public static String getTaskList(TaskList tasks, Date date, String keyWord) {
+    public static ArrayList<String> getTaskList(TaskList tasks, Date date, String keyWord) {
         ArrayList<String> lst = tasks.toString(date, keyWord);
         lst.add(0, "Here are the " + ((keyWord == null) ? "" : "matching ") + "tasks in your list" + ((date == null)
                 ? "" : " that occur on " + formatDate(date)) + ":");
-        return formatMultilineResponse(lst);
+        return lst;
     }
 
     /**
-     * Returns a String of a feedback message that task is marked as done.
+     * Returns a ArrayList String of a feedback message that task is marked as done.
      *
      * @param task Task that is done.
-     * @return Feedback message that task is marked as done.
+     * @return ArrayList feedback message that task is marked as done.
      */
-    public static String getDoneTask(Task task) {
-        return formatMultilineResponse(DONE_MSG, INDENT + task.toString());
+    public static ArrayList<String> getDoneTask(Task task) {
+        ArrayList<String> lst = new ArrayList<>();
+        lst.add(DONE_MSG);
+        lst.add(INDENT + task.toString());
+        return lst;
     }
 
     /**
-     * Returns a String of a feedback message that task is deleted.
+     * Returns a ArrayList String of a feedback message that task is deleted.
      *
      * @param task     Task that is deleted.
      * @param taskList
-     * @return
+     * @return ArrayList
      */
-    public static String getDeletedTask(Task task, TaskList taskList) {
-        return formatMultilineResponse(DELETED_MSG, INDENT + task.toString(), getListCount(taskList));
+    public static ArrayList<String> getDeletedTask(Task task, TaskList taskList) {
+        ArrayList<String> lst = new ArrayList<>();
+        lst.add(DELETED_MSG);
+        lst.add(INDENT + task.toString());
+        lst.add(getListCount(taskList));
+        return lst;
     }
 
     /**
-     * Returns a String of a feedback message that task is added to taskList.
+     * Returns a ArrayList String of a feedback message that task is added to taskList.
      *
      * @param task     Task that is added.
      * @param taskList TaskList
-     * @return Feedback message that task is added to taskList.
+     * @return ArrayList feedback message that task is added to taskList.
      */
-    public static String getAddTask(Task task, TaskList taskList) {
-        return formatMultilineResponse(ADD_MSG, INDENT + task.toString(), getListCount(taskList));
+    public static ArrayList<String> getAddTask(Task task, TaskList taskList) {
+        ArrayList<String> lst = new ArrayList<>();
+        lst.add(ADD_MSG);
+        lst.add(INDENT + task.toString());
+        lst.add(getListCount(taskList));
+        return lst;
     }
 
 }