Fixed collections ordering

refs https://github.com/TryGhost/Arch/issues/25

- When run against different DB Engines the returned order of collections belonging to a post is not consistent (SQLite vs MySQL). Having a primitive ordering by slug allows to keep the order compatible

ghost/collections/src/CollectionsService.ts

@@ -401,7 +401,11 @@ export class CollectionsService {
             filter: `posts:${postId}`
         });
 
-        return collections.map(collection => this.toDTO(collection));
+        return collections.map(collection => this.toDTO(collection))
+            .sort((a, b) => {
+                // NOTE: sorting is here to keep DB engine ordering consistent
+                return a.slug.localeCompare(b.slug);
+            });
     }
 
     async destroy(id: string): Promise<Collection | null> {

ghost/collections/test/collections.test.ts

@@ -117,15 +117,24 @@ describe('CollectionsService', function () {
         it('Can get collections for a post', async function () {
             const collection = await collectionsService.createCollection({
                 title: 'testing collections',
+                slug: 'testing-collections',
+                type: 'manual'
+            });
+
+            const collection2 = await collectionsService.createCollection({
+                title: 'testing collections 1',
+                slug: '1-testing-collections',
                 type: 'manual'
             });
 
             await collectionsService.addPostToCollection(collection.id, posts[0]);
+            await collectionsService.addPostToCollection(collection2.id, posts[0]);
 
             const collections = await collectionsService.getCollectionsForPost(posts[0].id);
 
-            assert.equal(collections.length, 1, 'There should be one collection');
-            assert.equal(collections[0].id, collection.id, 'Collection should be the correct one');
+            assert.equal(collections.length, 2, 'There should be one collection');
+            assert.equal(collections[0].id, collection2.id, 'Collections should be sorted by slug');
+            assert.equal(collections[1].id, collection.id, 'Collections should be sorted by slug');
         });
     });
 

ghost/core/test/e2e-api/admin/__snapshots__/posts.test.js.snap

@@ -1440,6 +1440,23 @@ Object {
       "codeinjection_foot": null,
       "codeinjection_head": null,
       "collections": Array [
+        Object {
+          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+          "description": null,
+          "feature_image": null,
+          "filter": null,
+          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+          "posts": Array [
+            Object {
+              "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
+              "sort_order": 0,
+            },
+          ],
+          "slug": "collection-to-add",
+          "title": "Collection to add.",
+          "type": "manual",
+          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
+        },
         Object {
           "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
           "description": "Collection with all posts",
@@ -1525,23 +1542,6 @@ Object {
           "type": "automatic",
           "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
         },
-        Object {
-          "created_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
-          "description": null,
-          "feature_image": null,
-          "filter": null,
-          "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
-          "posts": Array [
-            Object {
-              "id": StringMatching /\\[a-f0-9\\]\\{24\\}/,
-              "sort_order": 0,
-            },
-          ],
-          "slug": "collection-to-add",
-          "title": "Collection to add.",
-          "type": "manual",
-          "updated_at": StringMatching /\\\\d\\{4\\}-\\\\d\\{2\\}-\\\\d\\{2\\}T\\\\d\\{2\\}:\\\\d\\{2\\}:\\\\d\\{2\\}\\\\\\.\\\\d\\{3\\}Z/,
-        },
       ],
       "comment_id": Any<String>,
       "count": Object {

ghost/core/test/e2e-api/admin/posts.test.js

@@ -511,8 +511,8 @@ describe('Posts API', function () {
                 .matchBodySnapshot({
                     posts: [
                         Object.assign({}, matchPostShallowIncludes, {published_at: null}, {collections: [
-                            buildCollectionMatcher(18),
-                            collectionMatcher
+                            collectionMatcher,
+                            buildCollectionMatcher(18)
                         ]}
                         )
                     ]