feat(medusa): Attach or update cart sales channel (#1873)

What

Allow to create a cart with a sales channel, otherwise the default one is attached.
Also allow to update the sales channel on an existing cart and in that case the line items that does not belongs to the new sales channel attached are removed

How

Updating existing end points and service method to integrate the new requirements

Tests

Add new integration tests

Fixes CORE-270
Fixes CORE-272

Co-authored-by: Oliver Windall Juhl <59018053+olivermrbl@users.noreply.github.com>

integration-tests/api/factories/simple-cart-factory.ts

@@ -34,7 +34,7 @@ export type CartFactoryData = {
 export const simpleCartFactory = async (
   connection: Connection,
   data: CartFactoryData = {},
-  seed: number
+  seed?: number
 ): Promise<Cart> => {
   if (typeof seed !== "undefined") {
     faker.seed(seed)

integration-tests/api/factories/simple-sales-channel-factory.ts

@@ -8,6 +8,7 @@ export type SalesChannelFactoryData = {
   is_disabled?: boolean
   id?: string
   products?: Product[],
+  is_default?: boolean
 }
 
 export const simpleSalesChannelFactory = async (
@@ -36,12 +37,19 @@ export const simpleSalesChannelFactory = async (
     for (const product of data.products) {
       promises.push(
         manager.query(`
-          INSERT INTO product_sales_channel (product_id, sales_channel_id) VALUES ('${product.id}', '${salesChannel.id}');
+            INSERT INTO product_sales_channel (product_id, sales_channel_id)
+            VALUES ('${product.id}', '${salesChannel.id}');
         `)
       )
     }
     await Promise.all(promises)
   }
 
+  if (data.is_default) {
+    await manager.query(
+      `UPDATE store SET default_sales_channel_id = '${salesChannel.id}'`
+    )
+  }
+
   return salesChannel
 }