From beb44bbc2237b5bfcf95b0f1f5e43f437dcf8217 Mon Sep 17 00:00:00 2001
From: nqt230 <76938663+nqt230@users.noreply.github.com>
Date: Wed, 7 Sep 2022 22:29:20 +0800
Subject: [PATCH] Implement A-Assertions

- Add Java asserts to handle some previously unhandled exceptions
    - TaskList: Use asserts to ensure null tasks cannot be added to the list
    - Duke: Use asserts to ensure Duke initializes correctly
---
 src/main/java/duke/Main.java     | 3 +++
 src/main/java/duke/TaskList.java | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/src/main/java/duke/Main.java b/src/main/java/duke/Main.java
index a5f196de5f..bb9dd3f41d 100644
--- a/src/main/java/duke/Main.java
+++ b/src/main/java/duke/Main.java
@@ -17,6 +17,9 @@ public void start(Stage stage) {
         try {
             Duke.initialize();
 
+            assert Duke.getIsRunning()
+                    : "Duke.getIsRunning() should be true if Duke.initialize() runs correctly";
+
             FXMLLoader fxmlLoader = new FXMLLoader(Main.class.getResource("/view/MainWindow.fxml"));
             AnchorPane ap = fxmlLoader.load();
             Scene scene = new Scene(ap);
diff --git a/src/main/java/duke/TaskList.java b/src/main/java/duke/TaskList.java
index 40998ac15c..53f894f569 100644
--- a/src/main/java/duke/TaskList.java
+++ b/src/main/java/duke/TaskList.java
@@ -43,6 +43,9 @@ public static List<String> getTasksStrings() {
      * @return The task that was added.
      */
     public static Task addToList(Task task) {
+        assert task != null
+                : "a null Task should not be added to the list";
+
         tasks.add(task);
 
         return task;