Stage M7

apps/storefront/src/features/cart/cart-provider.tsx

@@ -16,6 +16,9 @@ interface CartState {
   addLine: (variantId: string, quantity?: number) => Promise<boolean>;
   setQuantity: (variantId: string, quantity: number) => Promise<void>;
   removeLine: (variantId: string) => Promise<void>;
+  /** Resolves to the updated cart, or null if the request itself failed. */
+  applyCode: (code: string) => Promise<Cart | null>;
+  removeCode: (code: string) => Promise<void>;
   refresh: () => Promise<void>;
 }
 
@@ -55,6 +58,28 @@ export function CartProvider({ locale, children }: { locale: Locale; children: R
   }, []);
 
   /** Re-reads the bag after something outside this provider changed it. */
+  /**
+   * Like `run`, but hands the caller the cart it produced.
+   *
+   * A discount code needs this: the request succeeding and the code *applying*
+   * are different outcomes, and only the returned cart can tell them apart.
+   */
+  const runReturning = useCallback(async (operation: () => Promise<Cart>): Promise<Cart | null> => {
+    setPending(true);
+    setError(null);
+
+    try {
+      const result = await operation();
+      setCart(result);
+      return result;
+    } catch (caught) {
+      setError(isApiClientError(caught) ? caught.message : 'Something went wrong.');
+      return null;
+    } finally {
+      setPending(false);
+    }
+  }, []);
+
   const refresh = useCallback(async () => {
     try {
       setCart(await browserApi.commerce.getCart(locale));
@@ -103,9 +128,13 @@ export function CartProvider({ locale, children }: { locale: Locale; children: R
       removeLine: async (variantId) => {
         await run(() => browserApi.commerce.removeCartLine(locale, variantId));
       },
+      applyCode: (code) => runReturning(() => browserApi.commerce.applyDiscountCode(locale, code)),
+      removeCode: async (code) => {
+        await run(() => browserApi.commerce.removeDiscountCode(locale, code));
+      },
       refresh,
     }),
-    [cart, loading, pending, error, locale, run, refresh],
+    [cart, loading, pending, error, locale, run, runReturning, refresh],
   );
 
   return <CartContext.Provider value={value}>{children}</CartContext.Provider>;