fix(event-handler): ignore return type from onSubscribe handler (#3888)

Author: dreamorosi

packages/event-handler/src/appsync-events/AppSyncEventsResolver.ts

@@ -173,10 +173,7 @@ class AppSyncEventsResolver extends Router {
     }
     const { handler } = routeHandlerOptions;
     try {
-      return await (handler as OnSubscribeHandler).apply(this, [
-        event,
-        context,
-      ]);
+      await (handler as OnSubscribeHandler).apply(this, [event, context]);
     } catch (error) {
       this.logger.error(`An error occurred in handler ${path}`, error);
       if (error instanceof UnauthorizedException) throw error;

packages/event-handler/tests/unit/AppSyncEventsResolver.test.ts

@@ -75,7 +75,7 @@ describe('Class: AppSyncEventsResolver', () => {
     expect(result).toEqual(null);
   });
 
-  it('returns the response of the onSubscribe handler', async () => {
+  it('ignores the response of the onSubscribe handler', async () => {
     // Prepare
     const app = new AppSyncEventsResolver({ logger: console });
     app.onSubscribe('/foo', async () => true);
@@ -87,7 +87,7 @@ describe('Class: AppSyncEventsResolver', () => {
     );
 
     // Assess
-    expect(result).toBe(true);
+    expect(result).toBe(undefined);
   });
 
   it.each([