Updated Saleor Provider (#356)

* Initial work, copied from the Shopify provider

* Added basis setup and type generation for the products queries

* refactor: adjust the types

* task: relax the Node.js constraint

* fix: page/product properties

* disable unknown fields

* mention Saleor in the README

* setup debugging for Next.js

* Check nextjs-commerce bug if no images are added for a product

* fix: client/server pecularities for env visibility

Must prefix with `NEXT_PUBLIC_` so that the API URL is
visible on the client

* re: make search work with Saleor API (WIP)

* task: update deps

* task: move to Webpack 5.x

* saleor: initial cart integration

* update deps

* saleor: shall the cart appear!

* task: remove deprecated packages

* saleor: adding/removing from the cart

* saleor: preliminary signup process

* saleor: fix the prices in the cart

* update deps

* update deps

* Added the options for a variant to the product page

* Mapped options to variants

* Mapped options to variants

* saleor: refine the auth process

* saleor: remove unused code

* saleor: handle customer find via refresh

temporary solution

* saleor: update deps

* saleor: fix the session handling

* saleor: fix the variants

* saleor: simplify the naming for GraphQL statements

* saleor: fix the type for collection

* saleor: arrange the error codes

* saleor: integrate collections

* saleor: fix product sorting

* saleor: set cookie location

* saleor: update the schema

* saleor: attach checkout to customer

* saleor: fix the checkout flow

* saleor: unify GraphQL naming approach

* task: update deps

* Add the env variables for saleor to the template

* task: prettier

* saleor: stub API for build/typescript compilation

thanks @cond0r

* task: temporarily disable for the `build`

* saleor: refactor GraphQL queries

* saleor: adjust the config

* task: update dependencies

* revert: Next.js to `10.0.9`

* saleor: fix the checkout fetch query

* task: update dependencies

* saleor: adapt for displaying featured products

* saleor: update the provider structure

* saleor: make the home page representable

* feature/cart: display the variant name (cond)

Co-authored-by: Patryk Zawadzki <patrys@room-303.com>
Co-authored-by: royderks <10717410+royderks@users.noreply.github.com>

framework/saleor/api/index.ts

@@ -0,0 +1,49 @@
+import type { CommerceAPIConfig } from '@commerce/api'
+
+import * as Const from '../const'
+
+if (!Const.API_URL) {
+  throw new Error(`The environment variable NEXT_SALEOR_API_URL is missing and it's required to access your store`)
+}
+
+if (!Const.API_CHANNEL) {
+  throw new Error(`The environment variable NEXT_SALEOR_CHANNEL is missing and it's required to access your store`)
+}
+
+import fetchGraphqlApi from './utils/fetch-graphql-api'
+
+export interface SaleorConfig extends CommerceAPIConfig {
+  storeChannel: string
+}
+
+const config: SaleorConfig = {
+  locale: 'en-US',
+  commerceUrl: Const.API_URL,
+  apiToken: Const.SALEOR_TOKEN,
+  cartCookie: Const.CHECKOUT_ID_COOKIE,
+  cartCookieMaxAge: 60 * 60 * 24 * 30,
+  fetch: fetchGraphqlApi,
+  customerCookie: '',
+  storeChannel: Const.API_CHANNEL,
+}
+
+import {
+  CommerceAPI,
+  getCommerceApi as commerceApi,
+} from '@commerce/api'
+
+import * as operations from './operations'
+
+export interface ShopifyConfig extends CommerceAPIConfig {}
+
+export const provider = { config, operations }
+
+export type Provider = typeof provider
+
+export type SaleorAPI<P extends Provider = Provider> = CommerceAPI<P>
+
+export function getCommerceApi<P extends Provider>(
+  customProvider: P = provider as any
+): SaleorAPI<P> {
+  return commerceApi(customProvider)
+}