feat(medusa): Add event emitter to ProductCollectionService (#3495)

* added event emit on ProductCollectionService CRUD, updated unit test

* productCollectionService code style fix

* Create .changeset/gold-fireants-look.md

---------

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

packages/medusa/src/services/__tests__/product-collection.js

@@ -1,5 +1,6 @@
 import { IdMap, MockRepository, MockManager } from "medusa-test-utils"
 import ProductCollectionService from "../product-collection"
+import { EventBusServiceMock } from "../__mocks__/event-bus"
 
 describe("ProductCollectionService", () => {
   describe("retrieve", () => {
@@ -15,6 +16,7 @@ describe("ProductCollectionService", () => {
     const productCollectionService = new ProductCollectionService({
       manager: MockManager,
       productCollectionRepository,
+      eventBusService: EventBusServiceMock,
     })
 
     beforeEach(async () => {
@@ -48,11 +50,13 @@ describe("ProductCollectionService", () => {
   describe("create", () => {
     const productCollectionRepository = MockRepository({
       findOne: query => Promise.resolve({ id: IdMap.getId("bathrobe") }),
+      create: query => Promise.resolve({ id: IdMap.getId("bathrobe") }),
     })
 
     const productCollectionService = new ProductCollectionService({
       manager: MockManager,
       productCollectionRepository,
+      eventBusService: EventBusServiceMock,
     })
 
     beforeEach(async () => {
@@ -60,12 +64,19 @@ describe("ProductCollectionService", () => {
     })
 
     it("successfully creates a product collection", async () => {
-      await productCollectionService.create({ title: "bathrobe" })
+      const entity = await productCollectionService.create({ title: "bathrobe" })
 
       expect(productCollectionRepository.create).toHaveBeenCalledTimes(1)
       expect(productCollectionRepository.create).toHaveBeenCalledWith({
         title: "bathrobe",
       })
+
+      expect(EventBusServiceMock.emit).toHaveBeenCalledTimes(1)
+      expect(EventBusServiceMock.emit).toHaveBeenCalledWith(
+        ProductCollectionService.Events.CREATED, {
+          id: entity.id,
+        }
+      )
     })
   })
 
@@ -82,6 +93,7 @@ describe("ProductCollectionService", () => {
     const productCollectionService = new ProductCollectionService({
       manager: MockManager,
       productCollectionRepository,
+      eventBusService: EventBusServiceMock,
     })
 
     beforeEach(async () => {
@@ -98,6 +110,13 @@ describe("ProductCollectionService", () => {
         id: IdMap.getId("bathrobe"),
         title: "bathrobes",
       })
+
+      expect(EventBusServiceMock.emit).toHaveBeenCalledTimes(1)
+      expect(EventBusServiceMock.emit).toHaveBeenCalledWith(
+        ProductCollectionService.Events.UPDATED, {
+          id: IdMap.getId("bathrobe"),
+        }
+      )
     })
 
     it("fails on non-existing product collection", async () => {
@@ -126,6 +145,7 @@ describe("ProductCollectionService", () => {
     const productCollectionService = new ProductCollectionService({
       manager: MockManager,
       productCollectionRepository,
+      eventBusService: EventBusServiceMock,
     })
 
     beforeEach(async () => {
@@ -139,6 +159,13 @@ describe("ProductCollectionService", () => {
       expect(productCollectionRepository.softRemove).toHaveBeenCalledWith({
         id: IdMap.getId("bathrobe"),
       })
+
+      expect(EventBusServiceMock.emit).toHaveBeenCalledTimes(1)
+      expect(EventBusServiceMock.emit).toHaveBeenCalledWith(
+        ProductCollectionService.Events.DELETED, {
+          id: IdMap.getId("bathrobe"),
+        }
+      )
     })
 
     it("succeeds idempotently", async () => {

packages/medusa/src/services/product-collection.ts

@@ -38,6 +38,14 @@ class ProductCollectionService extends TransactionBaseService {
   protected readonly productCollectionRepository_: typeof ProductCollectionRepository
   protected readonly productRepository_: typeof ProductRepository
 
+  static readonly Events = {
+    CREATED: "product-collection.created",
+    UPDATED: "product-collection.updated",
+    DELETED: "product-collection.deleted",
+    PRODUCTS_ADDED: "product-collection.products_added",
+    PRODUCTS_REMOVED: "product-collection.products_removed",
+  }
+
   constructor({
     productCollectionRepository,
     productRepository,
@@ -124,9 +132,16 @@ class ProductCollectionService extends TransactionBaseService {
       const collectionRepo = manager.withRepository(
         this.productCollectionRepository_
       )
+      let productCollection = collectionRepo.create(collection)
+      productCollection = await collectionRepo.save(productCollection);
 
-      const productCollection = collectionRepo.create(collection)
-      return await collectionRepo.save(productCollection)
+      await this.eventBus_
+        .withTransaction(manager)
+        .emit(ProductCollectionService.Events.CREATED, {
+          id: productCollection.id,
+        })
+
+      return productCollection
     })
   }
 
@@ -145,19 +160,27 @@ class ProductCollectionService extends TransactionBaseService {
         this.productCollectionRepository_
       )
 
-      const collection = await this.retrieve(collectionId)
+      let productCollection = await this.retrieve(collectionId)
 
       const { metadata, ...rest } = update
 
       if (metadata) {
-        collection.metadata = setMetadata(collection, metadata)
+        productCollection.metadata = setMetadata(productCollection, metadata)
       }
 
       for (const [key, value] of Object.entries(rest)) {
-        collection[key] = value
+        productCollection[key] = value
       }
 
-      return collectionRepo.save(collection)
+      productCollection = await collectionRepo.save(productCollection)
+
+      await this.eventBus_
+        .withTransaction(manager)
+        .emit(ProductCollectionService.Events.UPDATED, {
+          id: productCollection.id,
+        })
+
+      return productCollection
     })
   }
 
@@ -172,13 +195,19 @@ class ProductCollectionService extends TransactionBaseService {
         this.productCollectionRepository_
       )
 
-      const collection = await this.retrieve(collectionId)
+      const productCollection = await this.retrieve(collectionId)
 
-      if (!collection) {
+      if (!productCollection) {
         return Promise.resolve()
       }
 
-      await productCollectionRepo.softRemove(collection)
+      await productCollectionRepo.softRemove(productCollection)
+
+      await this.eventBus_
+        .withTransaction(manager)
+        .emit(ProductCollectionService.Events.DELETED, {
+          id: productCollection.id,
+      })
 
       return Promise.resolve()
     })
@@ -195,9 +224,18 @@ class ProductCollectionService extends TransactionBaseService {
 
       await productRepo.bulkAddToCollection(productIds, id)
 
-      return await this.retrieve(id, {
+      const productCollection = await this.retrieve(id, {
         relations: ["products"],
       })
+
+      await this.eventBus_
+        .withTransaction(manager)
+        .emit(ProductCollectionService.Events.PRODUCTS_ADDED, {
+          productCollection: productCollection,
+          productIds: productIds, 
+        })
+
+      return productCollection
     })
   }
 
@@ -212,6 +250,17 @@ class ProductCollectionService extends TransactionBaseService {
 
       await productRepo.bulkRemoveFromCollection(productIds, id)
 
+      const productCollection = await this.retrieve(id, {
+        relations: ["products"],
+      })
+
+      await this.eventBus_
+        .withTransaction(manager)
+        .emit(ProductCollectionService.Events.PRODUCTS_REMOVED, {
+          productCollection: productCollection,
+          productIds: productIds, 
+        })
+
       return Promise.resolve()
     })
   }