fix(medusa): Add free shipping functionality (#241)

packages/medusa/src/api/routes/store/carts/__tests__/update-cart.js

@@ -65,7 +65,7 @@ describe("POST /store/carts/:id", () => {
       expect(CartServiceMock.retrieve).toHaveBeenCalledWith(
         IdMap.getId("emptyCart"),
         {
-          relations: ["payment_sessions"],
+          relations: ["payment_sessions", "shipping_methods"],
         }
       )
       expect(CartServiceMock.retrieve).toHaveBeenCalledWith(

packages/medusa/src/api/routes/store/carts/update-cart.js

@@ -104,7 +104,7 @@ export default async (req, res) => {
 
     // If the cart has payment sessions update these
     const updated = await cartService.retrieve(id, {
-      relations: ["payment_sessions"],
+      relations: ["payment_sessions", "shipping_methods"],
     })
 
     if (updated.payment_sessions?.length && !value.region_id) {