feat: create trigger onEmptyCart (#129)

* feat: add prop onEmptyCart

* feat(readme): add prop onEmptyCart

* feat(tests): add test to prop onEmptyCart

Author: mariosantosdev

README.md

@@ -164,6 +164,7 @@ ReactDOM.render(
 | `onItemAdd`    | _No_     | Triggered on items added to your cart, unless the item already exists, then `onItemUpdate` will be invoked.                                                |
 | `onItemUpdate` | _No_     | Triggered on items updated in your cart, unless you are setting the quantity to `0`, then `onItemRemove` will be invoked.                                  |
 | `onItemRemove` | _No_     | Triggered on items removed from your cart.                                                                                                                 |
+| `onEmptyCart` | _No_     | Triggered on empty cart.                                                                                                                 |
 | `storage`      | _No_     | Must return `[getter, setter]`.                                                                                                                            |
 | `metadata`     | _No_     | Custom global state on the cart. Stored inside of `metadata`.                                                                                              |
 ## `useCart`

src/index.tsx

@@ -174,6 +174,7 @@ export const CartProvider: React.FC<{
   onItemAdd?: (payload: Item) => void;
   onItemUpdate?: (payload: object) => void;
   onItemRemove?: (id: Item["id"]) => void;
+  onEmptyCart?: () => void;
   storage?: (
     key: string,
     initialValue: string
@@ -187,6 +188,7 @@ export const CartProvider: React.FC<{
   onItemAdd,
   onItemUpdate,
   onItemRemove,
+  onEmptyCart,
   storage = useLocalStorage,
   metadata,
 }) => {
@@ -291,10 +293,11 @@ export const CartProvider: React.FC<{
     onItemRemove && onItemRemove(id);
   };
 
-  const emptyCart = () =>
-    dispatch({
-      type: "EMPTY_CART",
-    });
+  const emptyCart = () => {
+    dispatch({ type: "EMPTY_CART" });
+
+    onEmptyCart && onEmptyCart();
+  }
 
   const getItem = (id: Item["id"]) =>
     state.items.find((i: Item) => i.id === id);

test/index.test.tsx

@@ -406,6 +406,21 @@ describe("emptyCart", () => {
     expect(result.current.totalUniqueItems).toBe(0);
     expect(result.current.isEmpty).toBe(true);
   });
+
+  test("triggers onEmptyCart when empty cart", () => {
+    let called = false;
+
+    const wrapper: FC<Props> = ({ children }) => (
+      <CartProvider onEmptyCart={() => (called = true)}>
+        {children}
+      </CartProvider>
+    );
+
+    const { result } = renderHook(() => useCart(), { wrapper });
+
+    act(() => result.current.emptyCart());
+    expect(called).toBe(true);
+  });
 });
 
 describe("updateCartMetadata", () => {