Wrapped collection's post adding logic in transaction

refs https://github.com/TryGhost/Arch/issues/16

- Having transactional collection post updates makes sure there are no race conditions when updating collection_posts relations. Without the transactions collection was prone to update relations based on a stale state causing problems like described in the linked issue

ghost/collections/src/CollectionRepository.ts

@@ -1,8 +1,9 @@
 import {Collection} from './Collection';
 
 export interface CollectionRepository {
-    save(collection: Collection): Promise<void>
-    getById(id: string): Promise<Collection | null>
+    createTransaction(fn: (transaction: any) => Promise<any>): Promise<any>
+    save(collection: Collection, options?: {transaction: any}): Promise<void>
+    getById(id: string, options?: {transaction: any}): Promise<Collection | null>
     getBySlug(slug: string): Promise<Collection | null>
     getAll(options?: any): Promise<Collection[]>
 }

ghost/collections/src/CollectionsRepositoryInMemory.ts

@@ -6,6 +6,10 @@ export class CollectionsRepositoryInMemory extends InMemoryRepository<string, Co
         return entity.toJSON();
     }
 
+    createTransaction(cb: (transaction: any) => Promise<any>): Promise<any> {
+        return cb(null);
+    }
+
     async getBySlug(slug: string): Promise<Collection | null> {
         return this.store.find(item => item.slug === slug) || null;
     }

ghost/collections/src/CollectionsService.ts

@@ -92,6 +92,7 @@ type QueryOptions = {
     include?: string;
     page?: number;
     limit?: number;
+    transaction?: any;
 }
 
 interface PostsRepository {
@@ -253,32 +254,22 @@ export class CollectionsService {
     }
 
     private async addPostToMatchingCollections(post: CollectionPost) {
-        const collections = await this.collectionsRepository.getAll({
-            filter: 'type:automatic'
-        });
+        return await this.collectionsRepository.createTransaction(async (transaction) => {
+            const collections = await this.collectionsRepository.getAll({
+                filter: 'type:automatic',
+                transaction: transaction
+            });
 
-        for (const collection of collections) {
-            const added = await collection.addPost(post);
+            for (const collection of collections) {
+                const added = await collection.addPost(post);
 
-            if (added) {
-                await this.collectionsRepository.save(collection);
+                if (added) {
+                    await this.collectionsRepository.save(collection, {
+                        transaction: transaction
+                    });
+                }
             }
-        }
-    }
-
-    /**
-     * @description Updates all automatic collections. Can be time intensive and is a temporary solution
-     * while all of the events are mapped out and handled optimally
-     */
-    async updateCollections() {
-        const collections = await this.collectionsRepository.getAll({
-            filter: 'type:automatic'
         });
-
-        for (const collection of collections) {
-            await this.updateAutomaticCollectionItems(collection);
-            await this.collectionsRepository.save(collection);
-        }
     }
 
     async updatePostInMatchingCollections(postEdit: PostEditedEvent['data']) {

ghost/core/core/server/services/collections/BookshelfCollectionsRepository.js

@@ -12,6 +12,10 @@ module.exports = class BookshelfCollectionsRepository {
         this.#model = model;
     }
 
+    async createTransaction(cb) {
+        return this.#model.transaction(cb);
+    }
+
     /**
      * @param {string} id
      * @returns {Promise<Collection>}
@@ -40,9 +44,15 @@ module.exports = class BookshelfCollectionsRepository {
      * @param {object} [options]
      * @param {string} [options.filter]
      * @param {string} [options.order]
+     * @param {import('knex').Transaction} [options.transaction]
      */
     async getAll(options = {}) {
-        const models = await this.#model.findAll({...options, withRelated: ['posts']});
+        const models = await this.#model.findAll({
+            ...options,
+            transacting: options.transaction,
+            withRelated: ['posts']
+        });
+
         return await Promise.all(models.map(model => this.#modelToCollection(model)));
     }
 
@@ -65,9 +75,11 @@ module.exports = class BookshelfCollectionsRepository {
 
     /**
      * @param {Collection} collection
+     * @param {object} [options]
+     * @param {import('knex').Transaction} [options.transaction]
      * @returns {Promise<void>}
      */
-    async save(collection) {
+    async save(collection, options = {}) {
         if (collection.deleted) {
             await this.#model.destroy({id: collection.id});
             return;
@@ -85,13 +97,22 @@ module.exports = class BookshelfCollectionsRepository {
             updated_at: collection.updatedAt
         };
 
-        const existing = await this.#model.findOne({id: data.id}, {require: false});
+        const existing = await this.#model.findOne(
+            {id: data.id},
+            {
+                require: false,
+                transacting: options.transaction
+            }
+        );
 
         if (!existing) {
-            await this.#model.add(data);
+            await this.#model.add(data, {
+                transacting: options.transaction
+            });
         } else {
-            await this.#model.edit(data, {
-                id: data.id
+            return this.#model.edit(data, {
+                id: data.id,
+                transacting: options.transaction
             });
         }
     }