fix(server): avoid global rejection when event handler errors (#10467)

packages/backend/server/src/__tests__/event/eventbus.spec.ts

@@ -4,7 +4,7 @@ import { CLS_ID, ClsServiceManager } from 'nestjs-cls';
 import Sinon from 'sinon';
 
 import { EventBus, metrics } from '../../base';
-import { createTestingModule } from '../utils';
+import { createTestingModule, sleep } from '../utils';
 import { Listeners } from './provider';
 
 export const test = ava as TestFn<{
@@ -201,3 +201,55 @@ test('should continuously use the same request id', async t => {
 
   t.true(listeners.onRequestId.lastCall.returned('test-request-id'));
 });
+
+test('should throw when emitting async event with uncaught error', async t => {
+  const { eventbus } = t.context;
+
+  await t.throwsAsync(
+    () => eventbus.emitAsync('__test__.throw', { count: 0 }),
+    {
+      message: 'Error in event handler',
+    }
+  );
+});
+
+test('should suppress thrown error when emitting async event', async t => {
+  const { eventbus } = t.context;
+  const spy = Sinon.spy();
+  // @ts-expect-error internal event
+  const off = eventbus.on('error', spy);
+
+  const promise = eventbus.emitAsync('__test__.suppressThrow', {});
+  await t.notThrowsAsync(promise);
+
+  t.true(spy.calledOnce);
+  const args = spy.firstCall.args[0];
+  t.is(args.event, '__test__.suppressThrow');
+  t.deepEqual(args.payload, {});
+  t.is(args.error.message, 'Error in event handler');
+
+  const returns = await promise;
+  t.deepEqual(returns, [undefined]);
+
+  off();
+});
+
+test('should catch thrown error when emitting sync event', async t => {
+  const { eventbus } = t.context;
+
+  const spy = Sinon.spy();
+  // @ts-expect-error internal event
+  const off = eventbus.on('error', spy);
+  t.notThrows(() => eventbus.emit('__test__.throw', { count: 0 }));
+
+  // wait a tick
+  await sleep(1);
+
+  t.true(spy.calledOnce);
+  const args = spy.firstCall.args[0];
+  t.is(args.event, '__test__.throw');
+  t.deepEqual(args.payload, { count: 0 });
+  t.is(args.error.message, 'Error in event handler');
+
+  off();
+});

packages/backend/server/src/__tests__/event/provider.ts

@@ -8,6 +8,7 @@ declare global {
     '__test__.event': { count: number };
     '__test__.event2': { count: number };
     '__test__.throw': { count: number };
+    '__test__.suppressThrow': {};
     '__test__.requestId': {};
   }
 }
@@ -32,6 +33,11 @@ export class Listeners {
     throw new Error('Error in event handler');
   }
 
+  @OnEvent('__test__.suppressThrow', { suppressError: true })
+  onSuppressThrow() {
+    throw new Error('Error in event handler');
+  }
+
   @OnEvent('__test__.requestId')
   onRequestId() {
     const cls = ClsServiceManager.getClsService();

packages/backend/server/src/base/event/eventbus.ts

@@ -19,6 +19,12 @@ import { genRequestId } from '../utils';
 import { type EventName, type EventOptions } from './def';
 import { EventHandlerScanner } from './scanner';
 
+interface EventHandlerErrorPayload {
+  event: string;
+  payload: any;
+  error: Error;
+}
+
 /**
  * We use socket.io system to auto pub/sub on server to server broadcast events
  */
@@ -50,6 +56,9 @@ export class EventBus
 
   async onModuleInit() {
     this.bindEventHandlers();
+    this.emitter.on('error', ({ event, error }: EventHandlerErrorPayload) => {
+      this.logger.error(`Error happened when handling event ${event}`, error);
+    });
   }
 
   async onApplicationBootstrap() {
@@ -78,7 +87,16 @@ export class EventBus
    */
   emit<T extends EventName>(event: T, payload: Events[T]) {
     this.logger.log(`Dispatch event: ${event}`);
-    return this.emitter.emit(event, payload);
+
+    // NOTE(@forehalo):
+    //   Because all event handlers are wrapped in promisified metrics and cls context, they will always run in standalone tick.
+    //   In which way, if handler throws, an unhandled rejection will be triggered and end up with process exiting.
+    //   So we catch it here with `emitAsync`
+    this.emitter.emitAsync(event, payload).catch(e => {
+      this.emitter.emit('error', { event, payload, error: e });
+    });
+
+    return true;
   }
 
   /**
@@ -115,10 +133,11 @@ export class EventBus
             return await listener(payload);
           } catch (e) {
             if (suppressError) {
-              this.logger.error(
-                `Error happened when handling event ${signature}`,
-                e
-              );
+              this.emitter.emit('error', {
+                event,
+                payload,
+                error: e,
+              } as EventHandlerErrorPayload);
             } else {
               throw e;
             }

packages/backend/server/src/base/job/queue/index.ts

@@ -5,7 +5,7 @@ import { DynamicModule } from '@nestjs/common';
 
 import { Config } from '../../config';
 import { QueueRedis } from '../../redis';
-import { QUEUES } from './def';
+import { Queue, QUEUES } from './def';
 import { JobExecutor } from './executor';
 import { JobQueue } from './queue';
 import { JobHandlerScanner } from './scanner';
@@ -25,7 +25,15 @@ export class JobModule {
           },
           inject: [Config, QueueRedis],
         }),
-        BullModule.registerQueue(...QUEUES.map(name => ({ name }))),
+        BullModule.registerQueue(
+          ...QUEUES.map(name => {
+            if (name === Queue.NIGHTLY_JOB) {
+              // avoid nightly jobs been run multiple times
+              return { name, removeOnComplete: { age: 1000 * 60 * 60 } };
+            }
+            return { name };
+          })
+        ),
       ],
       providers: [JobQueue, JobExecutor, JobHandlerScanner],
       exports: [JobQueue],

packages/backend/server/src/plugins/payment/cron.ts

@@ -2,7 +2,7 @@ import { Injectable } from '@nestjs/common';
 import { Cron, CronExpression } from '@nestjs/schedule';
 import { PrismaClient } from '@prisma/client';
 
-import { EventBus, JobQueue, OnEvent, OnJob } from '../../base';
+import { EventBus, JobQueue, OnJob } from '../../base';
 import {
   SubscriptionPlan,
   SubscriptionRecurring,
@@ -126,6 +126,15 @@ export class SubscriptionCronJobs {
     });
 
     for (const subscription of subscriptions) {
+      await this.db.subscription.delete({
+        where: {
+          targetId_plan: {
+            targetId: subscription.targetId,
+            plan: subscription.plan,
+          },
+        },
+      });
+
       this.event.emit('user.subscription.canceled', {
         userId: subscription.targetId,
         plan: subscription.plan as SubscriptionPlan,
@@ -133,19 +142,4 @@ export class SubscriptionCronJobs {
       });
     }
   }
-
-  @OnEvent('user.subscription.canceled')
-  async handleUserSubscriptionCanceled({
-    userId,
-    plan,
-  }: Events['user.subscription.canceled']) {
-    await this.db.subscription.delete({
-      where: {
-        targetId_plan: {
-          targetId: userId,
-          plan,
-        },
-      },
-    });
-  }
 }