Error in product variant inventory service : Cannot read properties of null (reading 'id')

Stouffi commented 6 months ago

Bug report

Describe the bug

When a draft order contains a custom line item (i.e. a line item not related to any variant), this will make the endpoint GET /store/carts/[id-of-the-draft-order-cart] crash if an inventory service is registered in the modules of the project configuration.

System information

Medusa version (including plugins): 1.20.2

const plugins = [
  `medusa-fulfillment-manual`,
  `medusa-payment-manual`,
  {
    resolve: `@medusajs/file-local`,
    options: {
      upload_dir: "uploads",
    },
  },
  {
    resolve: "@medusajs/admin",
    /** @type {import('@medusajs/admin').PluginOptions} */
    options: {
      autoRebuild: true,
      develop: {
        open: process.env.OPEN_BROWSER !== "false",
      },
    },
  },
];

const modules = {
  inventoryService: {
    resolve: "@medusajs/inventory",
  },
  stockLocationService: {
    resolve: "@medusajs/stock-location",
  },
  /*eventBus: {
    resolve: "@medusajs/event-bus-redis",
    options: {
      redisUrl: REDIS_URL
    }
  },
  cacheService: {
    resolve: "@medusajs/cache-redis",
    options: {
      redisUrl: REDIS_URL
    }
  },*/
};

Node.js version: 20.11.1 Database: PostgreSQL 12 Operating system: 5.15.133.1-microsoft-standard-WSL2 Browser (if relevant):

Steps to reproduce the behavior

Setup a fresh medusa backend
Setup multi-warehouse related modules
Start the medusa backend (either with develop or start script)
Create a draft order from the admin dashboard and add at least one custom line item.
In the draft order page use the cart id from the raw data to GET localhost:9000/store/carts/[cart-id]

The api returns

{
"code": "unknown_error",
"type": "unknown_error",
"message": "An unknown error occurred."
}

The following error is printed in the backend logs

error:   Cannot read properties of null (reading 'id')
TypeError: Cannot read properties of null (reading 'id')
    at /home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:880:111
    at Array.map (<anonymous>)
    at ProductVariantInventoryService.<anonymous> (/home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:880:83)
    at step (/home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:59:23)
    at Object.next (/home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:40:53)
    at /home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:34:71
    at new Promise (<anonymous>)
    at __awaiter (/home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:30:12)
    at ProductVariantInventoryService.setVariantAvailability (/home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/services/product-variant-inventory.js:872:16)
    at /home/stouffi/projects/stouffi/stouffi-medusa/node_modules/@medusajs/medusa/dist/api/routes/store/carts/get-cart.js:193:69

Expected behavior

No errors and the cart data being returned by the api.

Additional context

This code from https://github.com/medusajs/medusa/blob/develop/packages/medusa/src/services/product-variant-inventory.ts#L832 is causing the bug.

const { variantInventoryMap, inventoryLocationMap } =
      await this.getAvailabilityContext(
        variants.map((v) => v.id), // v is nullable hence the error.
        salesChannelId,
        availabilityContext
      )

olivermrbl commented 6 months ago

Thanks for highlighting this. Would you be up for sending a PR with a fix?

Stouffi commented 6 months ago

I've tried to dig deeper and find out that a few other parts of the code may omit to check for null variant. I've made some changes on a fork based on a change in the type of LineItem Entity to add | null for variant relation as it was already the case for variant_id. This single change helped me to spot every piece of code affected by unchecked nulls. I'll submit a PR soon today or tomorrow. I added comments where I'm not sure about the expected behavior handling custom line items so that we can discuss it in reviews

medusajs / medusa