test: add e2e test for graceful shutdown (#2450)

* test: add e2e test for graceful shutdown

Co-authored-by: François <[email protected]>

---------

Co-authored-by: François <[email protected]>

e2e/graceful-shutdown.e2e-spec.ts

@@ -0,0 +1,66 @@
+import { ShutdownSignal } from '@nestjs/common';
+import { type NestApplicationContext } from '@nestjs/core';
+import * as request from 'supertest';
+import { bootstrapTestingModule } from './helper';
+import { sleep } from '../lib/utils';
+
+describe('Graceful shutdown', () => {
+  afterEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('should gracefully shutdown the application', async () => {
+    jest.spyOn(global, 'setTimeout');
+    const setHealthEndpoint = bootstrapTestingModule({
+      gracefulShutdownTimeoutMs: 64,
+    }).setHealthEndpoint;
+
+    const app = await setHealthEndpoint(({ healthCheck }) =>
+      healthCheck.check([]),
+    ).start();
+
+    const { status } = await request(app.getHttpServer()).get('/health');
+
+    expect(status).toBe(200);
+
+    let isClosed = false;
+    (app.close as NestApplicationContext['close'])(ShutdownSignal.SIGTERM).then(
+      () => {
+        isClosed = true;
+      },
+    );
+
+    await sleep(16);
+    // 1. setTimeout is called by the `GracefulShutdownService`
+    // 2. setTimeout is called above
+    expect(setTimeout).toHaveBeenCalledTimes(2);
+    expect(isClosed).toBe(false);
+    await sleep(16);
+    expect(isClosed).toBe(false);
+    await sleep(16);
+    expect(isClosed).toBe(false);
+    await sleep(64);
+    expect(isClosed).toBe(true);
+  });
+
+  it('should not delay the shutdown if the application if the timeout is 0', async () => {
+    jest.spyOn(global, 'setTimeout');
+    const setHealthEndpoint = bootstrapTestingModule({
+      gracefulShutdownTimeoutMs: 0,
+    }).setHealthEndpoint;
+
+    const app = await setHealthEndpoint(({ healthCheck }) =>
+      healthCheck.check([]),
+    ).start();
+
+    const { status } = await request(app.getHttpServer()).get('/health');
+
+    expect(status).toBe(200);
+
+    await (app.close as NestApplicationContext['close'])(
+      ShutdownSignal.SIGTERM,
+    );
+
+    expect(setTimeout).not.toHaveBeenCalled();
+  });
+});

e2e/helper/bootstrap-testing-module.ts

@@ -25,6 +25,7 @@ import {
   SequelizeHealthIndicator,
   TerminusModule,
   TypeOrmHealthIndicator,
+  type TerminusModuleOptions,
 } from '../../lib';
 import { type HealthCheckOptions } from '../../lib/health-check';
 import { MikroOrmHealthIndicator } from '../../lib/health-indicator/database/mikro-orm.health';
@@ -92,8 +93,12 @@ export type DynamicHealthEndpointFn = (
   ): Promise<INestApplication>;
 };
 
-export function bootstrapTestingModule() {
-  const imports: PropType<ModuleMetadata, 'imports'> = [TerminusModule];
+export function bootstrapTestingModule(
+  terminusModuleOptions: TerminusModuleOptions = {},
+) {
+  const imports: PropType<ModuleMetadata, 'imports'> = [
+    TerminusModule.forRoot(terminusModuleOptions),
+  ];
 
   const setHealthEndpoint: DynamicHealthEndpointFn = (func, options = {}) => {
     const testingModule = Test.createTestingModule({

lib/graceful-shutdown-timeout/graceful-shutdown-timeout.service.ts

@@ -29,7 +29,7 @@ export class GracefulShutdownService implements BeforeApplicationShutdown {
   }
 
   async beforeApplicationShutdown(signal: string) {
-    this.logger.log(`Received termination signal ${signal}`);
+    this.logger.log(`Received termination signal ${signal || ''}`);
 
     if (signal === 'SIGTERM') {
       this.logger.log(

lib/terminus.module.ts

@@ -1,5 +1,8 @@
-import { type DynamicModule, Module } from '@nestjs/common';
-import { TERMINUS_GRACEFUL_SHUTDOWN_TIMEOUT } from './graceful-shutdown-timeout/graceful-shutdown-timeout.service';
+import { type DynamicModule, Module, type Provider } from '@nestjs/common';
+import {
+  GracefulShutdownService,
+  TERMINUS_GRACEFUL_SHUTDOWN_TIMEOUT,
+} from './graceful-shutdown-timeout/graceful-shutdown-timeout.service';
 import { HealthCheckService } from './health-check';
 import { getErrorLoggerProvider } from './health-check/error-logger/error-logger.provider';
 import { ERROR_LOGGERS } from './health-check/error-logger/error-loggers.provider';
@@ -9,7 +12,7 @@ import { DiskUsageLibProvider } from './health-indicator/disk/disk-usage-lib.pro
 import { HEALTH_INDICATORS } from './health-indicator/health-indicators.provider';
 import { type TerminusModuleOptions } from './terminus-options.interface';
 
-const providers = [
+const baseProviders: Provider[] = [
   ...ERROR_LOGGERS,
   DiskUsageLibProvider,
   HealthCheckExecutor,
@@ -26,7 +29,7 @@ const exports_ = [HealthCheckService, ...HEALTH_INDICATORS];
  * @publicApi
  */
 @Module({
-  providers: [...providers, getErrorLoggerProvider(), getLoggerProvider()],
+  providers: [...baseProviders, getErrorLoggerProvider(), getLoggerProvider()],
   exports: exports_,
 })
 export class TerminusModule {
@@ -37,17 +40,24 @@ export class TerminusModule {
       gracefulShutdownTimeoutMs = 0,
     } = options;
 
+    const providers: Provider[] = [
+      ...baseProviders,
+      getErrorLoggerProvider(errorLogStyle),
+      getLoggerProvider(logger),
+    ];
+
+    if (gracefulShutdownTimeoutMs > 0) {
+      providers.push({
+        provide: TERMINUS_GRACEFUL_SHUTDOWN_TIMEOUT,
+        useValue: gracefulShutdownTimeoutMs,
+      });
+
+      providers.push(GracefulShutdownService);
+    }
+
     return {
       module: TerminusModule,
-      providers: [
-        ...providers,
-        getErrorLoggerProvider(errorLogStyle),
-        getLoggerProvider(logger),
-        {
-          provide: TERMINUS_GRACEFUL_SHUTDOWN_TIMEOUT,
-          useValue: gracefulShutdownTimeoutMs,
-        },
-      ],
+      providers,
       exports: exports_,
     };
   }