fix: retain additional data in async responses

src/GenericResource.ts

@@ -46,6 +46,7 @@ export class GenericResource<
   private body: GenericBody<R> = { data: {} as any }
   private pendingData?: unknown
   private pendingDataCollected = false
+  private pendingAdditional: Record<string, any>[] = []
   private res?: Response
   public resource: R
   public collects?: typeof Resource<T>
@@ -313,6 +314,7 @@ export class GenericResource<
         rootKey
       ) as GenericBody<R>
       this.body = this.applySerializePlugins(this.body) as GenericBody<R>
+      this.applyPendingAdditional()
     }
 
     // if (this.collects) console.log(this.body, this.constructor.name, this.collects.name)
@@ -384,6 +386,7 @@ export class GenericResource<
         rootKey
       ) as GenericBody<R>
       this.body = this.applySerializePlugins(this.body) as GenericBody<R>
+      this.applyPendingAdditional()
     }
 
     return undefined
@@ -429,25 +432,34 @@ export class GenericResource<
   additional<X extends Record<string, any>>(extra: X) {
     this.called.additional = true
     this.json()
+    this.pendingAdditional.push({ ...extra })
 
-    const extraData = extra.data
+    if (this.called.json) {
+      this.applyPendingAdditional()
+    }
 
-    delete extra.data
-    delete extra.pagination
+    return this
+  }
 
-    const payloadKey = this.getPayloadKey()
-    if (extraData && payloadKey && typeof this.body[payloadKey] !== 'undefined') {
-      this.body[payloadKey] = Array.isArray(this.body[payloadKey])
-        ? [...this.body[payloadKey], ...extraData]
-        : { ...this.body[payloadKey], ...extraData }
-    }
+  private applyPendingAdditional() {
+    for (const extra of this.pendingAdditional.splice(0)) {
+      const extraData = extra.data
 
-    this.body = {
-      ...this.body,
-      ...extra,
-    }
+      delete extra.data
+      delete extra.pagination
 
-    return this
+      const payloadKey = this.getPayloadKey()
+      if (extraData && payloadKey && typeof this.body[payloadKey] !== 'undefined') {
+        this.body[payloadKey] = Array.isArray(this.body[payloadKey])
+          ? [...this.body[payloadKey], ...extraData]
+          : { ...this.body[payloadKey], ...extraData }
+      }
+
+      this.body = {
+        ...this.body,
+        ...extra,
+      }
+    }
   }
 
   /**

src/Resource.ts

@@ -39,6 +39,7 @@ export class Resource<R extends ResourceData | NonCollectible = ResourceData> ex
   [key: string]: any;
   private body: ResourceBody<R> = { data: {} as any }
   private pendingData?: unknown
+  private pendingAdditional: Record<string, any>[] = []
   private res?: Response
   public resource: R
   protected withResponseContext?: {
@@ -235,6 +236,7 @@ export class Resource<R extends ResourceData | NonCollectible = ResourceData> ex
 
       this.body = appendRootProperties(this.body, customMeta, rootKey) as ResourceBody<R>
       this.body = this.applySerializePlugins(this.body) as ResourceBody<R>
+      this.applyPendingAdditional()
     }
 
     return this
@@ -284,6 +286,7 @@ export class Resource<R extends ResourceData | NonCollectible = ResourceData> ex
 
       this.body = appendRootProperties(this.body, customMeta, rootKey) as ResourceBody<R>
       this.body = this.applySerializePlugins(this.body) as ResourceBody<R>
+      this.applyPendingAdditional()
     }
 
     return undefined
@@ -329,23 +332,32 @@ export class Resource<R extends ResourceData | NonCollectible = ResourceData> ex
   additional<X extends Record<string, any>>(extra: X) {
     this.called.additional = true
     this.json()
+    this.pendingAdditional.push({ ...extra })
 
-    const payloadKey = this.getPayloadKey()
-
-    if (extra.data && payloadKey && typeof this.body[payloadKey] !== 'undefined') {
-      this.body[payloadKey] = Array.isArray(this.body[payloadKey])
-        ? [...this.body[payloadKey], ...extra.data]
-        : { ...this.body[payloadKey], ...extra.data }
-    }
-
-    this.body = {
-      ...this.body,
-      ...extra,
+    if (this.called.json) {
+      this.applyPendingAdditional()
     }
 
     return this
   }
 
+  private applyPendingAdditional() {
+    for (const extra of this.pendingAdditional.splice(0)) {
+      const payloadKey = this.getPayloadKey()
+
+      if (extra.data && payloadKey && typeof this.body[payloadKey] !== 'undefined') {
+        this.body[payloadKey] = Array.isArray(this.body[payloadKey])
+          ? [...this.body[payloadKey], ...extra.data]
+          : { ...this.body[payloadKey], ...extra.data }
+      }
+
+      this.body = {
+        ...this.body,
+        ...extra,
+      }
+    }
+  }
+
   /**
    * Build a response object, optionally accepting a raw response to mutate in withResponse.
    */

src/ResourceCollection.ts

@@ -45,6 +45,7 @@ export class ResourceCollection<
   private body: CollectionBody<R> = { data: [] as any }
   private pendingData?: unknown
   private pendingDataCollected = false
+  private pendingAdditional: Record<string, any>[] = []
   private res?: Response
   public resource: R
   public collects?: typeof Resource<T>
@@ -322,6 +323,7 @@ export class ResourceCollection<
         rootKey
       ) as CollectionBody<R>
       this.body = this.applySerializePlugins(this.body) as CollectionBody<R>
+      this.applyPendingAdditional()
     }
 
     return this
@@ -395,6 +397,7 @@ export class ResourceCollection<
         rootKey
       ) as CollectionBody<R>
       this.body = this.applySerializePlugins(this.body) as CollectionBody<R>
+      this.applyPendingAdditional()
     }
 
     return undefined
@@ -481,22 +484,31 @@ export class ResourceCollection<
   additional<X extends Record<string, any>>(extra: X) {
     this.called.additional = true
     this.json()
+    this.pendingAdditional.push({ ...extra })
 
-    delete extra.cursor
-    delete extra.pagination
+    if (this.called.json) {
+      this.applyPendingAdditional()
+    }
 
-    const payloadKey = this.getPayloadKey()
+    return this
+  }
 
-    if (extra.data && payloadKey && Array.isArray(this.body[payloadKey])) {
-      this.body[payloadKey] = [...this.body[payloadKey], ...extra.data] as never
-    }
+  private applyPendingAdditional() {
+    for (const extra of this.pendingAdditional.splice(0)) {
+      delete extra.cursor
+      delete extra.pagination
 
-    this.body = {
-      ...this.body,
-      ...extra,
-    }
+      const payloadKey = this.getPayloadKey()
 
-    return this
+      if (extra.data && payloadKey && Array.isArray(this.body[payloadKey])) {
+        this.body[payloadKey] = [...this.body[payloadKey], ...extra.data] as never
+      }
+
+      this.body = {
+        ...this.body,
+        ...extra,
+      }
+    }
   }
 
   /**

tests/express.spec.ts

@@ -352,6 +352,28 @@ describe('Connect-style Requests (Express)', () => {
             return await new ProfileCollection(models, res).response().setStatusCode(202)
         })
 
+        app.get('/additional/test', async (_, res) => {
+            return await new UserResource({
+                id: 2,
+                name: 'John',
+                profile: {
+                    id: 20,
+                    displayName: 'John Doe',
+                },
+            }, res)
+                .additional({ data: { fromAdditional: true }, status: 'success' })
+                .response()
+        })
+
+        app.get('/all/additional/test', async (_, res) => {
+            return await new ProfileCollection(models, res)
+                .additional({
+                    data: [{ id: 3, displayName: 'Additional' }],
+                    status: 'success',
+                })
+                .response()
+        })
+
         await request(app).get('/test').expect(202).expect({
             data: {
                 id: 1,
@@ -366,6 +388,16 @@ describe('Connect-style Requests (Express)', () => {
         await request(app).get('/all/test').expect(202).expect({
             data: models.all(),
         })
+
+        await request(app).get('/additional/test').expect({
+            data: { fromAdditional: true },
+            status: 'success',
+        })
+
+        await request(app).get('/all/additional/test').expect({
+            data: [{ id: 3, displayName: 'Additional' }],
+            status: 'success',
+        })
     })
 
     it('should allow class-level withResponse hook to customize headers/status/body', async () => {

tests/generic.spec.ts

@@ -129,4 +129,25 @@ describe('Generic Core', () => {
             ],
         })
     })
+
+    it('should retain additional data after async serialization', async () => {
+        class AsyncGenericResource extends GenericResource {
+            data(): any {
+                return Promise.resolve({ id: 1, name: 'Jane' })
+            }
+        }
+
+        const body = await new AsyncGenericResource({ id: 1, name: 'Jane' })
+            .additional({ data: { fromAdditional: true }, status: 'success' })
+            .response()
+
+        expect(body).toEqual({
+            data: {
+                id: 1,
+                name: 'Jane',
+                fromAdditional: true,
+            },
+            status: 'success',
+        })
+    })
 })