Vendure provider (#223)

* Minimal list/detail views working with Vendure

* Implement useCart/useAddItem

* Implement useUpdateItem & useRemoveItem

* Implement useSearch

* Add operations codegen, tidy up

* Dummy checkout page

* Implement auth/customer hooks

* Use env var for Shop API url

* Add some documentation

* Improve error handling

* Optimize preview image size

* Fix accidental change

* Update Vendure provider to latest changes

* Vendure provider: split out gql operations, remove unused files

* Update Vendure provider readme

* Add local next.config to Vendure provider, update docs

* Update to use demo server

* Fix build errors

* Use proxy for vendure api

* Simplify instructions in Vendure readme

* Refactor Vendure checkout api handler

* Improve image quality

framework/vendure/cart/use-update-item.tsx

@@ -0,0 +1,78 @@
+import { useCallback } from 'react'
+import { HookFetcherContext, MutationHookContext } from '@commerce/utils/types'
+import { CommerceError, ValidationError } from '@commerce/utils/errors'
+import useUpdateItem, { UseUpdateItem } from '@commerce/cart/use-update-item'
+import {
+  Cart,
+  CartItemBody,
+  LineItem,
+  UpdateCartItemBody,
+} from '@commerce/types'
+import useCart from './use-cart'
+import {
+  AdjustOrderLineMutation,
+  AdjustOrderLineMutationVariables,
+} from '../schema'
+import { normalizeCart } from '../lib/normalize'
+import { adjustOrderLineMutation } from '../lib/mutations/adjust-order-line-mutation'
+
+export default useUpdateItem as UseUpdateItem<typeof handler>
+
+export const handler = {
+  fetchOptions: {
+    query: adjustOrderLineMutation,
+  },
+  async fetcher(context: HookFetcherContext<UpdateCartItemBody<CartItemBody>>) {
+    const { input, options, fetch } = context
+    const variables: AdjustOrderLineMutationVariables = {
+      quantity: input.item.quantity || 1,
+      orderLineId: input.itemId,
+    }
+    const { adjustOrderLine } = await fetch<AdjustOrderLineMutation>({
+      ...options,
+      variables,
+    })
+
+    if (adjustOrderLine.__typename === 'Order') {
+      return normalizeCart(adjustOrderLine)
+    }
+    throw new CommerceError(adjustOrderLine)
+  },
+  useHook: ({
+    fetch,
+  }: MutationHookContext<Cart | null, UpdateCartItemBody<CartItemBody>>) => (
+    ctx: {
+      item?: LineItem
+      wait?: number
+    } = {}
+  ) => {
+    const { item } = ctx
+    const { mutate } = useCart()
+
+    return useCallback(
+      async function addItem(input: Partial<CartItemBody>) {
+        const itemId = item?.id
+        const productId = input.productId ?? item?.productId
+        const variantId = input.productId ?? item?.variantId
+        if (!itemId || !productId || !variantId) {
+          throw new ValidationError({
+            message: 'Invalid input used for this operation',
+          })
+        }
+        const data = await fetch({
+          input: {
+            item: {
+              productId,
+              variantId,
+              quantity: input.quantity,
+            },
+            itemId,
+          },
+        })
+        await mutate(data, false)
+        return data
+      },
+      [fetch, mutate]
+    )
+  },
+}