Improve code quality

src/main/java/DukeException.java

@@ -5,6 +5,6 @@ public DukeException() {
 
     @Override
     public String getMessage(){
-        return "\u2639 OOPS!!! I'm sorry, but I don't know what that means :-(";
+        return "\u2639 OOPS!!! I'm sorry, but I don't recognise that command :-(";
     }
 }

src/main/java/EmptyDescriptionException.java

@@ -0,0 +1,10 @@
+public class EmptyDescriptionException extends DukeException {
+    public EmptyDescriptionException() {
+        super();
+    }
+
+    @Override
+    public String getMessage(){
+        return "\u2639 OOPS!!! The description cannot be empty.";
+    }
+}

src/main/java/Parser.java

@@ -22,25 +22,27 @@ public class Parser {
      */
     public String parseInput(String input) throws DukeException {
         String msg = "";
+        String[] inputParts = input.split(" ");
+        String command = inputParts[0];
         if (input.equals("list")) {
             msg = taskList.showList();
-        } else if (input.split(" ")[0].equals("done")) {
-            int taskNum = Integer.parseInt(input.split(" ")[1]);
+        } else if (command.equals("done")) {
+            int taskNum = Integer.parseInt(inputParts[1]);
             msg = taskList.done(taskNum);
-        } else if (input.split(" ")[0].equals("todo") ||
-                input.split(" ")[0].equals("event") ||
-                input.split(" ")[0].equals("deadline")) {
+        } else if (command.equals("todo") ||
+                command.equals("event") ||
+                command.equals("deadline")) {
             msg = taskList.add(input);
-        } else if (input.split(" ")[0].equals("delete")) {
-            int taskNum = Integer.parseInt(input.split(" ")[1]);
+        } else if (command.equals("delete")) {
+            int taskNum = Integer.parseInt(inputParts[1]);
             msg = taskList.delete(taskNum);
-        } else if (input.split(" ")[0].equals("find")) {
-            String query = input.split(" ")[1];
+        } else if (command.equals("find")) {
+            String query = inputParts[1];
             msg = taskList.find(query);
-        } else if (input.split(" ")[0].equals("bye")) {
+        } else if (command.equals("bye")) {
             msg = "Bye. Hope to serve you again soon!";
         } else {
-            throw new DukeException();
+            throw new UnrecognisedCommandException();
         }
         assert ! msg.equals("") : "Response is not empty";
         return msg;

src/main/java/TaskList.java

@@ -34,30 +34,28 @@ public TaskList(Ui ui, Storage storage) {
      * @throws DukeException If string format is invalid.
      */
     public String add(String s) throws DukeException {
-        String typeOfTask = s.split(" ", 2)[0];
+        String[] taskParts = s.split(" ", 2);
+        String taskType = taskParts[0];
         Task toAdd = new Task();
-        if (typeOfTask.equals("todo")) {
+        if (taskType.equals("todo")) {
             try {
-                String task = s.split(" ", 2)[1];
-                toAdd = new Todo(task);
+                toAdd = new Todo(taskParts[1]);
             } catch (ArrayIndexOutOfBoundsException e) {
-                throw new TodoException();
+                throw new EmptyDescriptionException();
             }
-        } else if (typeOfTask.equals("event")) {
+        } else if (taskType.equals("event")) {
             try {
-                String task = s.split(" ", 2)[1];
-                String[] taskParts = task.split(" /at ");
-                toAdd = new Event(taskParts[0], taskParts[1]);
+                String[] taskInfo = taskParts[1].split(" /at ");
+                toAdd = new Event(taskInfo[0], taskInfo[1]);
             } catch (ArrayIndexOutOfBoundsException e) {
-                throw new EventException();
+                throw new EmptyDescriptionException();
             }
-        } else if (typeOfTask.equals("deadline")) {
+        } else if (taskType.equals("deadline")) {
             try {
-                String task = s.split(" ", 2)[1];
-                String[] taskParts = task.split(" /by ");
-                toAdd = new Deadline(taskParts[0], taskParts[1]);
+                String[] taskInfo = taskParts[1].split(" /by ");
+                toAdd = new Deadline(taskInfo[0], taskInfo[1]);
             } catch (ArrayIndexOutOfBoundsException e) {
-                throw new DeadlineException();
+                throw new EmptyDescriptionException();
             }
         }
         taskList.add(toAdd);

src/main/java/Ui.java

@@ -1,23 +1,8 @@
-import java.io.InputStream;
-import java.util.Scanner;
-
 /**
  * Represents an interface to facilitate user input and output.
  */
 public class Ui {
-    private Scanner sc;
-
     public Ui() {}
-
-    /**
-     * Prints string.
-     *
-     * @param s String to print.
-     */
-    public void print(String s) {
-        System.out.println(s);
-    }
-
     /**
      * Prints error message.
      *
@@ -27,22 +12,4 @@ public void print(String s) {
     public String showError(Exception e) {
         return "Something went wrong: " + e.getMessage();
     }
-
-    /**
-     * Sets input stream.
-     *
-     * @param in Input stream to set.
-     */
-    public void setInput(InputStream in) {
-        sc = new Scanner(in);
-    }
-
-    /**
-     * Returns next line from input stream.
-     *
-     * @return Next line from input stream.
-     */
-    public String getLine() {
-        return sc.nextLine();
-    }
 }

src/main/java/UnrecognisedCommandException.java

@@ -0,0 +1,10 @@
+public class UnrecognisedCommandException extends DukeException {
+    public UnrecognisedCommandException() {
+        super();
+    }
+
+    @Override
+    public String getMessage(){
+        return "\u2639 OOPS!!! I'm sorry, but I don't know what that means :-(";
+    }
+}

tutorials/gradleTutorial.md

@@ -1,4 +1,4 @@
-de# Gradle Tutorial
+# Gradle Tutorial
 
 Gradle is a _build automation tool_ used to automate build processes. There are many ways of integrating Gradle into a project. In this guide, we will be using the _Gradle wrapper_.