Fixed tag.deleted event mapping

https://github.com/TryGhost/Arch/issues/90

- When a tag.deleted event is emitted the original 'data' object does not contain an 'id' property. The logic in collections service assumes the id would be present to update the collections efficiently.

ghost/model-to-domain-event-interceptor/src/ModelToDomainEventInterceptor.ts

@@ -94,7 +94,10 @@ export class ModelToDomainEventInterceptor {
             });
             break;
         case 'tag.deleted':
-            event = TagDeletedEvent.create({id: data.id, slug: data.attributes.slug});
+            event = TagDeletedEvent.create({
+                id: data.id || data._previousAttributes?.id,
+                slug: data.attributes?.slug || data._previousAttributes?.slug
+            });
             break;
         default:
         }

ghost/model-to-domain-event-interceptor/test/model-to-domain-event-interceptor.test.ts

@@ -192,6 +192,34 @@ describe('ModelToDomainEventInterceptor', function () {
             interceptedEvent = event;
         });
 
+        eventRegistry.emit('tag.deleted', {
+            _previousAttributes: {
+                id: '1234-deleted',
+                slug: 'tag-slug'
+            }
+        });
+
+        await DomainEvents.allSettled();
+
+        assert.ok(interceptedEvent);
+    });
+
+    it('Intercepts tag.deleted Model event without an id property and dispatches TagDeletedEvent Domain event', async function () {
+        let eventRegistry = new EventRegistry();
+        const modelToDomainEventInterceptor = new ModelToDomainEventInterceptor({
+            ModelEvents: eventRegistry,
+            DomainEvents: DomainEvents
+        });
+
+        modelToDomainEventInterceptor.init();
+
+        let interceptedEvent;
+        DomainEvents.subscribe(TagDeletedEvent, (event: TagDeletedEvent) => {
+            assert.equal(event.id, '1234-deleted');
+            assert.equal(event.data.slug, 'tag-slug');
+            interceptedEvent = event;
+        });
+
         eventRegistry.emit('tag.deleted', {
             id: '1234-deleted',
             attributes: {