Food Ordering App: Edge Cases and Testing

Food Ordering App: Edge Cases and Testing

Edge cases make the food ordering app production-ready. Here are the cases to handle and how to test.

Edge Cases to Handle

1. Empty Cart

if (Object.keys(cart).length === 0) {
  cartDiv.innerHTML = "<p>Your cart is empty</p>";
  return;
}
``
#### 2. No Search Results

```js
if (filteredItems.length === 0) {
  menuDiv.innerHTML = "<p>No items found</p>";
  return;
}
``
#### 3. Quantity 0

```js
function changeQuantity(id, delta) {
  cart[id] = (cart[id] || 0) + delta;
  if (cart[id] <= 0) delete cart[id];
  renderCart();
}
``
#### 4. Decimal Prices

```js
const total = Object.entries(cart).reduce((sum, [id, qty]) => {
  const item = menu.find((m) => m.id === parseInt(id));
  return sum + item.price * qty;
}, 0);
// format: total.toFixed(2)
``
#### 5. Clear Cart

```js
function clearCart() {
  cart = {};
  renderCart();
}
``
#### 6. Checkout Confirmation

```js
function checkout() {
  if (Object.keys(cart).length === 0) return;
  const total = calculateTotal();
  alert(`Order placed! Total: ₹${total}`);
  clearCart();
}
``
### How to Test

1. **Add items to cart**: verify the cart updates.
2. **Change quantity**: verify the total updates.
3. **Remove items**: verify the cart updates.
4. **Search**: verify only matching items show.
5. **Filter veg/non-veg**: verify the correct items show.
6. **Filter by category**: verify only that category shows.
7. **Empty cart**: verify the empty message shows.
8. **No results**: verify the no results message shows.
9. **Clear cart**: verify the cart is emptied.
10. **Checkout**: verify the confirmation and cart clearing.

### The Takeaway

Handle edge cases: empty cart, no search results, quantity 0 (remove), decimal prices (toFixed), clear cart, and checkout confirmation. Test each feature manually: add, remove, quantity, search, filters, empty states, clear, and checkout. Edge cases and testing show production-readiness.