Memoize commerce config

lib/commerce/index.tsx

@@ -35,7 +35,20 @@ export function CommerceProvider({ children, config }: CommerceProps) {
     throw new Error('CommerceProvider requires a valid config object')
   }
 
-  return <Commerce.Provider value={config}>{children}</Commerce.Provider>
+  // Because the config is an object, if the parent re-renders this provider
+  // will re-render every consumer unless we memoize the config
+  const cfg = useMemo(
+    () => ({
+      fetcher: config.fetcher,
+      locale: config.locale,
+      cartCookie: config.cartCookie,
+    }),
+    // Even though the fetcher is a function, it's never expected to be
+    // added dynamically (We should say that on the docs for this hook)
+    [config.fetcher, config.locale, config.cartCookie]
+  )
+
+  return <Commerce.Provider value={cfg}>{children}</Commerce.Provider>
 }
 
 export function useCommerce<T extends CommerceConfig>() {