feat(core-flows,types,utils,medusa): Translate tax lines (#14359)

* Include locale field for traslations on tax line workflows

* Translate tax lines in getItemTaxLinesStep with new util

* Update tax calculation context, so that we pass locale to third party tax providers if they want to return translated tax rates

* Apply translations to tax lines on product and variant tax middlewares

* Cart management translations tests

* Update tax lines when order locale gets updated

* Add changeset

* Get tranlsated tax lines step

* Fix wording

* Mutate ref directly

* Update order tax lines translations upon order locale change

* Claims translations tests

* Update tax lines upon draft order locale update

* Exchange tests for tax lines translations

* Order edits test for tax line translation

* Add tests for shipping methods tax line translations on various order flows

* Returns shipping method translations tests

* Execute update in parallel

* Use TranslationFeatureFlag.key

* Fix feature flag import

* Add @medusajs/medusa dependency for feature flag usage

* Revert "Add @medusajs/medusa dependency for feature flag usage"

This reverts commit e8897aed0a88f83c1034ac73e817e4222250a2c9.

* Use feature flag string directly

* Fix test

* Parallelize tax line translations application

integration-tests/http/__tests__/order/admin/order-translation.spec.ts

@@ -36,13 +36,16 @@ medusaIntegrationTestRunner({
       let returnShippingOption: { id: string }
       let outboundShippingOption: { id: string }
       let inventoryItem: { id: string }
+      let taxRate: { id: string; name: string }
 
       beforeAll(async () => {
         appContainer = getContainer()
       })
 
       beforeEach(async () => {
-        await setupTaxStructure(appContainer.resolve(Modules.TAX))
+        const taxStructure = await setupTaxStructure(
+          appContainer.resolve(Modules.TAX)
+        )
         await createAdminUser(dbConnection, adminHeaders, appContainer)
         const publishableKey = await generatePublishableKey(appContainer)
         storeHeaders = generateStoreHeaders({ publishableKey })
@@ -255,7 +258,16 @@ medusaIntegrationTestRunner({
           )
         ).data.shipping_option
 
-        // Create translations for product, variants, and shipping options
+        const taxRatesResponse = await api.get(
+          `/admin/tax-rates?tax_region_id=${taxStructure.us.children.cal.province.id}`,
+          adminHeaders
+        )
+        taxRate = taxRatesResponse.data.tax_rates.find(
+          (rate: { is_default: boolean; code: string }) =>
+            rate.is_default && rate.code === "CADEFAULT"
+        )
+
+        // Create translations for product and variants
         await api.post(
           "/admin/translations/batch",
           {
@@ -318,6 +330,22 @@ medusaIntegrationTestRunner({
                   name: "Test-Versandoption",
                 },
               },
+              {
+                reference_id: taxRate.id,
+                reference: "tax_rate",
+                locale_code: "fr-FR",
+                translations: {
+                  name: "Taux par défaut CA",
+                },
+              },
+              {
+                reference_id: taxRate.id,
+                reference: "tax_rate",
+                locale_code: "de-DE",
+                translations: {
+                  name: "CA Standardsteuersatz",
+                },
+              },
             ],
           },
           adminHeaders
@@ -521,6 +549,119 @@ medusaIntegrationTestRunner({
           )
         })
       })
+
+      describe("Tax line translations", () => {
+        it("should translate tax line descriptions when order locale is updated", async () => {
+          // Create order with French locale
+          const order = await createOrderFromCart("fr-FR")
+
+          // Verify tax lines exist and have French translation
+          expect(order.items[0].tax_lines).toBeDefined()
+          expect(order.items[0].tax_lines.length).toBe(1)
+          expect(order.items[0].tax_lines[0]).toEqual(
+            expect.objectContaining({
+              description: "Taux par défaut CA",
+              rate: 5,
+              code: "CADEFAULT",
+            })
+          )
+
+          // Update order locale to German
+          await api.post(
+            `/admin/orders/${order.id}`,
+            { locale: "de-DE" },
+            adminHeaders
+          )
+
+          // Fetch updated order
+          const updatedOrder = (
+            await api.get(`/admin/orders/${order.id}`, adminHeaders)
+          ).data.order
+
+          // Verify tax lines are translated to German
+          expect(updatedOrder.items[0].tax_lines.length).toBe(1)
+          expect(updatedOrder.items[0].tax_lines[0]).toEqual(
+            expect.objectContaining({
+              description: "CA Standardsteuersatz",
+              rate: 5,
+              code: "CADEFAULT",
+            })
+          )
+        })
+
+        it("should preserve tax line translations when order is created with locale", async () => {
+          // Create order with French locale
+          const order = await createOrderFromCart("fr-FR")
+
+          // Verify tax lines are translated from the start
+          expect(order.items[0].tax_lines).toBeDefined()
+          expect(order.items[0].tax_lines.length).toBeGreaterThan(0)
+          expect(order.items[0].tax_lines[0]).toEqual(
+            expect.objectContaining({
+              description: "Taux par défaut CA",
+              rate: 5,
+              code: "CADEFAULT",
+            })
+          )
+        })
+
+        it("should use original tax line description when order has no locale", async () => {
+          // Create order without locale
+          const order = await createOrderFromCart()
+
+          // Verify tax lines use original description
+          expect(order.items[0].tax_lines).toBeDefined()
+          expect(order.items[0].tax_lines.length).toBeGreaterThan(0)
+          expect(order.items[0].tax_lines[0]).toEqual(
+            expect.objectContaining({
+              description: "CA Default Rate",
+              rate: 5,
+              code: "CADEFAULT",
+            })
+          )
+        })
+
+        it("should translate shipping method tax lines when order locale is updated", async () => {
+          // Create order with French locale
+          const order = await createOrderFromCart("fr-FR")
+
+          // Verify shipping method tax lines exist and are translated
+          expect(order.shipping_methods).toBeDefined()
+          expect(order.shipping_methods.length).toBeGreaterThan(0)
+          if (order.shipping_methods[0].tax_lines?.length > 0) {
+            expect(order.shipping_methods[0].tax_lines[0]).toEqual(
+              expect.objectContaining({
+                description: "Taux par défaut CA",
+                rate: 5,
+                code: "CADEFAULT",
+              })
+            )
+
+            // Update order locale to German
+            await api.post(
+              `/admin/orders/${order.id}`,
+              { locale: "de-DE" },
+              adminHeaders
+            )
+
+            // Fetch updated order
+            const updatedOrder = (
+              await api.get(`/admin/orders/${order.id}`, adminHeaders)
+            ).data.order
+
+            // Verify shipping method tax lines are translated
+            if (updatedOrder.shipping_methods[0].tax_lines?.length > 0) {
+              expect(updatedOrder.shipping_methods[0].tax_lines[0]).toEqual(
+                expect.objectContaining({
+                  description: "CA Standardsteuersatz",
+                  rate: 5,
+                  code: "CADEFAULT",
+                })
+              )
+            }
+          }
+        })
+      })
     })
   },
 })