Adding toDo app functionability

Closes #2 (closed)

public/js/app.js

-// Obtener referencia a los elementos del DOM
+// Get reference to DOM elements
 const taskList = document.querySelector('.task-list ul');
 const newTaskForm = document.querySelector('form');
 
@@ -78,7 +78,7 @@ newTaskForm.addEventListener('submit', async (e) => {
 
     const newTodo = await res.json();
     taskList.appendChild(createTaskElement(newTodo));
-    input.value = ''; // Limpiar el campo de entrada
+    input.value = ''; // Clear input field
   } catch (err) {
     console.error('Error adding task:', err);
   }
@@ -86,6 +86,12 @@ newTaskForm.addEventListener('submit', async (e) => {
 
 // Mark task as completed
 async function markAsDone(taskId, isDone) {
+  // Input sanitation 
+  if (isNaN(parseInt(taskId, 10)) && typeof(isDone) === 'boolean') {
+    console.error('Invalid task ID or task status is invalid');
+    return;
+  }
+
   try {
     const res = await fetch(`/api/todos/${taskId}/done`, {
       method: 'PUT',
@@ -104,6 +110,12 @@ async function markAsDone(taskId, isDone) {
 
 // Erase task
 async function deleteTask(taskId) {
+  // Input sanitation 
+  if (isNaN(parseInt(taskId, 10))) {
+    console.error('Invalid task ID');
+    return;
+  }
+
   try {
     const res = await fetch(`/api/todos/${taskId}`, {
       method: 'DELETE'
@@ -122,6 +134,12 @@ async function deleteTask(taskId) {
 
 // Edit task
 async function updateTask(taskId, newDescription) {
+  // Input sanitation 
+  if (isNaN(parseInt(taskId, 10)) && typeof(newDescription) === 'string') {
+    console.error('Invalid task ID or new description is not string');
+    return;
+  }
+
   try {
     const res = await fetch(`/api/todos/${taskId}/description`, {
       method: 'PUT',