bug fixes for cart actions

lib/bigcommerce/api/cart.ts

@@ -146,14 +146,18 @@ const cartApi: BigcommerceApiHandler<Cart> = async (req, res, config) => {
         `/v3/carts/${cartId}/items/${itemId}`,
         { method: 'DELETE' }
       )
+      const data = result?.data ?? null
 
-      // Update the cart cookie
       res.setHeader(
         'Set-Cookie',
-        getCartCookie(config.cartCookie, cartId, config.cartCookieMaxAge)
+        data
+          ? // Update the cart cookie
+            getCartCookie(config.cartCookie, cartId, config.cartCookieMaxAge)
+          : // Remove the cart cookie if the cart was removed (empty items)
+            getCartCookie(config.cartCookie)
       )
 
-      return res.status(200).json({ data: result?.data })
+      return res.status(200).json({ data })
     }
   } catch (error) {
     console.error(error)

lib/bigcommerce/cart/index.tsx

@@ -16,7 +16,7 @@ export const CartProvider: FC = ({ children }) => {
 }
 
 export function useCart() {
-  const cart = useCommerceCart<Cart>()
+  const cart = useCommerceCart<Cart | null>()
 
   // Uses a getter to only calculate the prop when required
   // cart.data is also a getter and it's better to not trigger it early

lib/bigcommerce/cart/use-add-item.tsx

@@ -23,7 +23,7 @@ export default function useAddItem() {
   const fn = useCartAddItem<Cart, AddItemBody>(fetcher)
   const addItem: typeof fn = async (input) => {
     const data = await fn(input)
-    mutate(data)
+    await mutate(data, false)
     return data
   }
 

lib/bigcommerce/cart/use-remove-item.tsx

@@ -5,7 +5,10 @@ import { Cart, useCart } from '.'
 
 export type { ItemBody, RemoveItemBody }
 
-function fetcher(fetch: Fetcher<Cart>, { itemId }: RemoveItemBody) {
+export function fetcher(
+  fetch: Fetcher<Cart | null>,
+  { itemId }: RemoveItemBody
+) {
   return fetch({
     url: '/api/bigcommerce/cart',
     method: 'DELETE',
@@ -15,10 +18,10 @@ function fetcher(fetch: Fetcher<Cart>, { itemId }: RemoveItemBody) {
 
 export default function useRemoveItem() {
   const { mutate } = useCart()
-  const fn = useCartRemoveItem<Cart, RemoveItemBody>(fetcher)
+  const fn = useCartRemoveItem<Cart | null, RemoveItemBody>(fetcher)
   const removeItem: typeof fn = async (input) => {
     const data = await fn(input)
-    mutate(data)
+    await mutate(data, false)
     return data
   }
 

lib/bigcommerce/cart/use-update-item.tsx

@@ -1,18 +1,22 @@
 import type { Fetcher } from '@lib/commerce'
 import { default as useCartUpdateItem } from '@lib/commerce/cart/use-update-item'
 import type { ItemBody, UpdateItemBody } from '../api/cart'
+import { fetcher as removeFetcher } from './use-remove-item'
 import { Cart, useCart } from '.'
 
-export type { ItemBody, UpdateItemBody }
+export type UpdateItemInput = Partial<{ id: string } & ItemBody>
 
-function fetcher(fetch: Fetcher<Cart>, { itemId, item }: UpdateItemBody) {
-  if (
-    item.quantity &&
-    (!Number.isInteger(item.quantity) || item.quantity! < 1)
-  ) {
-    throw new Error(
-      'The item quantity has to be a valid integer greater than 0'
-    )
+function fetcher(
+  fetch: Fetcher<Cart | null>,
+  { itemId, item }: UpdateItemBody
+) {
+  if (Number.isInteger(item.quantity)) {
+    // Also allow the update hook to remove an item if the quantity is lower than 1
+    if (item.quantity! < 1) {
+      return removeFetcher(fetch, { itemId })
+    }
+  } else if (item.quantity) {
+    throw new Error('The item quantity has to be a valid integer')
   }
 
   return fetch({
@@ -22,11 +26,18 @@ function fetcher(fetch: Fetcher<Cart>, { itemId, item }: UpdateItemBody) {
   })
 }
 
-export default function useUpdateItem() {
+export default function useUpdateItem(item: any = {}) {
   const { mutate } = useCart()
-  const fn = useCartUpdateItem<Cart, UpdateItemBody>(fetcher)
-  const updateItem: typeof fn = async (input) => {
-    const data = await fn(input)
+  const fn = useCartUpdateItem<Cart | null, UpdateItemBody>(fetcher)
+  const updateItem = async (input: UpdateItemInput) => {
+    const data = await fn({
+      itemId: input.id ?? item.id,
+      item: {
+        productId: input.productId ?? item.product_id,
+        variantId: input.productId ?? item.variant_id,
+        quantity: input.quantity,
+      },
+    })
     await mutate(data, false)
     return data
   }

lib/commerce/cart/index.tsx

@@ -20,10 +20,11 @@ const CartProvider: FC<CartProviderProps> = ({ children, query, url }) => {
 
 function useCart<C>() {
   const { fetcher: fetch, cartCookie } = useCommerce()
-  const fetcher = (url?: string, query?: string) => fetch({ url, query })
-  const cartId = Cookies.get(cartCookie)
+  const fetcher = (url?: string, query?: string) => {
+    return Cookies.get(cartCookie) ? fetch({ url, query }) : null
+  }
   const { url, query } = useContext(CartContext)
-  const response = useSWR(() => (cartId ? [url, query] : null), fetcher, {
+  const response = useSWR([url, query], fetcher, {
     revalidateOnFocus: false,
   })