Fix aborted$ event and add completed$ event to KibanaRequest (elastic#73898)

Author: joshdover

docs/development/core/server/kibana-plugin-core-server.kibanarequestevents.completed_.md

@@ -0,0 +1,18 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+[Home](./index.md) &gt; [kibana-plugin-core-server](./kibana-plugin-core-server.md) &gt; [KibanaRequestEvents](./kibana-plugin-core-server.kibanarequestevents.md) &gt; [completed$](./kibana-plugin-core-server.kibanarequestevents.completed_.md)
+
+## KibanaRequestEvents.completed$ property
+
+Observable that emits once if and when the request has been completely handled.
+
+<b>Signature:</b>
+
+```typescript
+completed$: Observable<void>;
+```
+
+## Remarks
+
+The request may be considered completed if: - A response has been sent to the client; or - The request was aborted.
+

docs/development/core/server/kibana-plugin-core-server.kibanarequestevents.md

@@ -17,4 +17,5 @@ export interface KibanaRequestEvents
 |  Property | Type | Description |
 |  --- | --- | --- |
 |  [aborted$](./kibana-plugin-core-server.kibanarequestevents.aborted_.md) | <code>Observable&lt;void&gt;</code> | Observable that emits once if and when the request has been aborted. |
+|  [completed$](./kibana-plugin-core-server.kibanarequestevents.completed_.md) | <code>Observable&lt;void&gt;</code> | Observable that emits once if and when the request has been completely handled. |
 

src/core/server/http/integration_tests/request.test.ts

@@ -23,6 +23,7 @@ import { HttpService } from '../http_service';
 import { contextServiceMock } from '../../context/context_service.mock';
 import { loggingSystemMock } from '../../logging/logging_system.mock';
 import { createHttpServer } from '../test_utils';
+import { schema } from '@kbn/config-schema';
 
 let server: HttpService;
 
@@ -195,6 +196,96 @@ describe('KibanaRequest', () => {
         expect(nextSpy).toHaveBeenCalledTimes(0);
         expect(completeSpy).toHaveBeenCalledTimes(1);
       });
+
+      it('does not complete before response has been sent', async () => {
+        const { server: innerServer, createRouter, registerOnPreAuth } = await server.setup(
+          setupDeps
+        );
+        const router = createRouter('/');
+
+        const nextSpy = jest.fn();
+        const completeSpy = jest.fn();
+
+        registerOnPreAuth((req, res, toolkit) => {
+          req.events.aborted$.subscribe({
+            next: nextSpy,
+            complete: completeSpy,
+          });
+          return toolkit.next();
+        });
+
+        router.post(
+          { path: '/', validate: { body: schema.any() } },
+          async (context, request, res) => {
+            expect(completeSpy).not.toHaveBeenCalled();
+            return res.ok({ body: 'ok' });
+          }
+        );
+
+        await server.start();
+
+        await supertest(innerServer.listener).post('/').send({ data: 'test' }).expect(200);
+
+        expect(nextSpy).toHaveBeenCalledTimes(0);
+        expect(completeSpy).toHaveBeenCalledTimes(1);
+      });
+    });
+
+    describe('completed$', () => {
+      it('emits once and completes when response is sent', async () => {
+        const { server: innerServer, createRouter } = await server.setup(setupDeps);
+        const router = createRouter('/');
+
+        const nextSpy = jest.fn();
+        const completeSpy = jest.fn();
+
+        router.get({ path: '/', validate: false }, async (context, req, res) => {
+          req.events.completed$.subscribe({
+            next: nextSpy,
+            complete: completeSpy,
+          });
+
+          expect(nextSpy).not.toHaveBeenCalled();
+          expect(completeSpy).not.toHaveBeenCalled();
+          return res.ok({ body: 'ok' });
+        });
+
+        await server.start();
+
+        await supertest(innerServer.listener).get('/').expect(200);
+        expect(nextSpy).toHaveBeenCalledTimes(1);
+        expect(completeSpy).toHaveBeenCalledTimes(1);
+      });
+
+      it('emits once and completes when response is aborted', async (done) => {
+        expect.assertions(2);
+        const { server: innerServer, createRouter } = await server.setup(setupDeps);
+        const router = createRouter('/');
+
+        const nextSpy = jest.fn();
+
+        router.get({ path: '/', validate: false }, async (context, req, res) => {
+          req.events.completed$.subscribe({
+            next: nextSpy,
+            complete: () => {
+              expect(nextSpy).toHaveBeenCalledTimes(1);
+              done();
+            },
+          });
+
+          expect(nextSpy).not.toHaveBeenCalled();
+          await delay(30000);
+          return res.ok({ body: 'ok' });
+        });
+
+        await server.start();
+
+        const incomingRequest = supertest(innerServer.listener)
+          .get('/')
+          // end required to send request
+          .end();
+        setTimeout(() => incomingRequest.abort(), 50);
+      });
     });
   });
 });

src/core/server/http/router/request.ts

@@ -64,6 +64,16 @@ export interface KibanaRequestEvents {
    * Observable that emits once if and when the request has been aborted.
    */
   aborted$: Observable<void>;
+
+  /**
+   * Observable that emits once if and when the request has been completely handled.
+   *
+   * @remarks
+   * The request may be considered completed if:
+   * - A response has been sent to the client; or
+   * - The request was aborted.
+   */
+  completed$: Observable<void>;
 }
 
 /**
@@ -186,11 +196,16 @@ export class KibanaRequest<
 
   private getEvents(request: Request): KibanaRequestEvents {
     const finish$ = merge(
-      fromEvent(request.raw.req, 'end'), // all data consumed
+      fromEvent(request.raw.res, 'finish'), // Response has been sent
       fromEvent(request.raw.req, 'close') // connection was closed
     ).pipe(shareReplay(1), first());
+
+    const aborted$ = fromEvent<void>(request.raw.req, 'aborted').pipe(first(), takeUntil(finish$));
+    const completed$ = merge<void, void>(finish$, aborted$).pipe(shareReplay(1), first());
+
     return {
-      aborted$: fromEvent<void>(request.raw.req, 'aborted').pipe(first(), takeUntil(finish$)),
+      aborted$,
+      completed$,
     } as const;
   }
 

src/core/server/server.api.md

@@ -1071,6 +1071,7 @@ export class KibanaRequest<Params = unknown, Query = unknown, Body = unknown, Me
 // @public
 export interface KibanaRequestEvents {
     aborted$: Observable<void>;
+    completed$: Observable<void>;
 }
 
 // @public