fix(medusa): Handle variant error during line item generation (#5145)

* fix(medusa): Handle variant error during line item generation

* improve and tests

* cleanup

* update messages

* Create few-masks-draw.md

* change error type

* fix unit tests

.changeset/few-masks-draw.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+fix(medusa): Handle variant error during line item generation

packages/medusa/src/services/__tests__/line-item.js

@@ -4,6 +4,9 @@ import LineItemService from "../line-item"
 import { PricingServiceMock } from "../__mocks__/pricing"
 import { ProductVariantServiceMock } from "../__mocks__/product-variant"
 import { RegionServiceMock } from "../__mocks__/region"
+
+const unknownVariantId = "unknown-variant"
+
 ;[true, false].forEach((isTaxInclusiveEnabled) => {
   describe(`tax inclusive flag set to: ${isTaxInclusiveEnabled}`, () => {
     describe("LineItemService", () => {
@@ -480,16 +483,21 @@ describe("LineItemService", () => {
         })
       })
     })
+
     describe("generate", () => {
       const lineItemRepository = MockRepository({
         create: (data) => data,
       })
 
       const cartRepository = MockRepository({
-        findOne: () =>
+        findOne: ({ id }) =>
-          Promise.resolve({
+          Promise.resolve(
+            !id
+              ? null
+              : {
                   region_id: IdMap.getId("test-region"),
-          }),
+                }
+          ),
       })
 
       const regionService = {
@@ -521,7 +529,12 @@ describe("LineItemService", () => {
         },
         getRegionPrice: () => 100,
         list: jest.fn().mockImplementation(async (selector) => {
-          return (selector.id || []).map((id) => {
+          return (selector.id || [])
+            .map((id) => {
+              if (id === unknownVariantId) {
+                return null
+              }
+
               return {
                 id,
                 title: "Test variant",
@@ -531,6 +544,7 @@ describe("LineItemService", () => {
                 },
               }
             })
+            .filter(Boolean)
         }),
       }
 
@@ -570,6 +584,48 @@ describe("LineItemService", () => {
         jest.clearAllMocks()
       })
 
+      it("should not succeed to generate a line item if a variant id is not provided", async () => {
+        const err = await lineItemService
+          .generate(
+            [
+              {
+                variantId: "",
+                quantity: 1,
+              },
+            ],
+            {
+              region_id: IdMap.getId("test-region"),
+            }
+          )
+          .catch((e) => e)
+
+        expect(err).toBeDefined()
+        expect(err.message).toEqual(
+          "Unable to generate the line item because one or more required argument(s) are missing. Ensure a variant id is passed for each variant"
+        )
+      })
+
+      it("should not succeed to generate a line item if a variant id is not found", async () => {
+        const err = await lineItemService
+          .generate(
+            [
+              {
+                variantId: unknownVariantId,
+                quantity: 1,
+              },
+            ],
+            {
+              region_id: IdMap.getId("test-region"),
+            }
+          )
+          .catch((e) => e)
+
+        expect(err).toBeDefined()
+        expect(err.message).toEqual(
+          "Unable to generate the line items, some variant has not been found: unknown-variant"
+        )
+      })
+
       it("successfully create a line item with tax inclusive set to false", async () => {
         await lineItemService.generate(
           IdMap.getId("test-variant"),

packages/medusa/src/services/line-item.ts

@@ -210,6 +210,7 @@ class LineItemService extends TransactionBaseService {
           quantity
         )
 
+        // Resolve data
         const data = isString(variantIdOrData)
           ? {
               variantId: variantIdOrData,
@@ -235,6 +236,7 @@ class LineItemService extends TransactionBaseService {
           resolvedData.map((d) => [d.variantId, d])
         )
 
+        // Retrieve variants
         const variants = await this.productVariantService_.list(
           {
             id: resolvedData.map((d) => d.variantId),
@@ -244,6 +246,23 @@ class LineItemService extends TransactionBaseService {
           }
         )
 
+        // Validate that all variants has been found
+        const inputDataVariantId = new Set(resolvedData.map((d) => d.variantId))
+        const foundVariants = new Set(variants.map((v) => v.id))
+        const notFoundVariants = new Set(
+          [...inputDataVariantId].filter((x) => !foundVariants.has(x))
+        )
+
+        if (notFoundVariants.size) {
+          throw new MedusaError(
+            MedusaError.Types.INVALID_DATA,
+            `Unable to generate the line items, some variant has not been found: ${[
+              ...notFoundVariants,
+            ].join(", ")}`
+          )
+        }
+
+        // Prepare data to retrieve variant pricing
         const variantsMap = new Map<string, ProductVariant>()
         const variantsToCalculatePricingFor: {
           variantId: string
@@ -277,6 +296,7 @@ class LineItemService extends TransactionBaseService {
             })
         }
 
+        // Generate line items
         const generatedItems: LineItem[] = []
 
         for (const variantData of resolvedData) {
@@ -601,22 +621,46 @@ class LineItemService extends TransactionBaseService {
     regionIdOrContext: T extends string ? string : GenerateLineItemContext,
     quantity?: number
   ): void | never {
+    const errorMessage =
+      "Unable to generate the line item because one or more required argument(s) are missing"
+
     if (isString(variantIdOrData)) {
       if (!quantity || !regionIdOrContext || !isString(regionIdOrContext)) {
         throw new MedusaError(
-          MedusaError.Types.UNEXPECTED_STATE,
+          MedusaError.Types.INVALID_DATA,
-          "The generate method has been called with a variant id but one of the argument quantity or regionId is missing. Please, provide the variantId, quantity and regionId."
+          `${errorMessage}. Ensure quantity, regionId, and variantId are passed`
         )
       }
-    } else {
+
+      if (!variantIdOrData) {
+        throw new MedusaError(
+          MedusaError.Types.INVALID_DATA,
+          `${errorMessage}. Ensure variant id is passed`
+        )
+      }
+      return
+    }
+
     const resolvedContext = regionIdOrContext as GenerateLineItemContext
 
-      if (!resolvedContext.region_id) {
+    if (!resolvedContext?.region_id) {
       throw new MedusaError(
-          MedusaError.Types.UNEXPECTED_STATE,
+        MedusaError.Types.INVALID_DATA,
-          "The generate method has been called with the data but the context is missing either region_id or region. Please provide at least one of region or region_id."
+        `${errorMessage}. Ensure region or region_id are passed`
       )
     }
+
+    const variantsData = Array.isArray(variantIdOrData)
+      ? variantIdOrData
+      : [variantIdOrData]
+
+    const hasMissingVariantId = variantsData.some((d) => !d?.variantId)
+
+    if (hasMissingVariantId) {
+      throw new MedusaError(
+        MedusaError.Types.INVALID_DATA,
+        `${errorMessage}. Ensure a variant id is passed for each variant`
+      )
     }
   }
 }