feat(core): Unify application components shutdown (#8097)

## Summary

Add `ShutdownService` and `OnShutdown` decorator for more unified way to
shutdown different components. Use this new way in the following
components:

- HTTP(S) server
- Pruning service
- Push connection
- License

---------

Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/cli/test/unit/shutdown/Shutdown.service.test.ts

@@ -0,0 +1,127 @@
+import { ApplicationError, ErrorReporterProxy } from 'n8n-workflow';
+import { mock } from 'jest-mock-extended';
+import type { ServiceClass } from '@/shutdown/Shutdown.service';
+import { ShutdownService } from '@/shutdown/Shutdown.service';
+import Container from 'typedi';
+
+class MockComponent {
+	onShutdown() {}
+}
+
+describe('ShutdownService', () => {
+	let shutdownService: ShutdownService;
+	let mockComponent: MockComponent;
+	let onShutdownSpy: jest.SpyInstance;
+	let mockErrorReporterProxy: jest.SpyInstance;
+
+	beforeEach(() => {
+		shutdownService = new ShutdownService(mock());
+		mockComponent = new MockComponent();
+		Container.set(MockComponent, mockComponent);
+		onShutdownSpy = jest.spyOn(mockComponent, 'onShutdown');
+		mockErrorReporterProxy = jest.spyOn(ErrorReporterProxy, 'error').mockImplementation(() => {});
+	});
+
+	describe('shutdown', () => {
+		it('should signal shutdown', () => {
+			shutdownService.register(10, {
+				serviceClass: MockComponent as unknown as ServiceClass,
+				methodName: 'onShutdown',
+			});
+			shutdownService.shutdown();
+			expect(onShutdownSpy).toBeCalledTimes(1);
+		});
+
+		it('should signal shutdown in the priority order', async () => {
+			class MockService {
+				onShutdownHighPrio() {}
+
+				onShutdownLowPrio() {}
+			}
+
+			const order: string[] = [];
+			const mockService = new MockService();
+			Container.set(MockService, mockService);
+
+			jest.spyOn(mockService, 'onShutdownHighPrio').mockImplementation(() => order.push('high'));
+			jest.spyOn(mockService, 'onShutdownLowPrio').mockImplementation(() => order.push('low'));
+
+			shutdownService.register(100, {
+				serviceClass: MockService as unknown as ServiceClass,
+				methodName: 'onShutdownHighPrio',
+			});
+
+			shutdownService.register(10, {
+				serviceClass: MockService as unknown as ServiceClass,
+				methodName: 'onShutdownLowPrio',
+			});
+
+			shutdownService.shutdown();
+			await shutdownService.waitForShutdown();
+			expect(order).toEqual(['high', 'low']);
+		});
+
+		it('should throw error if shutdown is already in progress', () => {
+			shutdownService.register(10, {
+				methodName: 'onShutdown',
+				serviceClass: MockComponent as unknown as ServiceClass,
+			});
+			shutdownService.shutdown();
+			expect(() => shutdownService.shutdown()).toThrow('App is already shutting down');
+		});
+
+		it('should report error if component shutdown fails', async () => {
+			const componentError = new Error('Something went wrong');
+			onShutdownSpy.mockImplementation(() => {
+				throw componentError;
+			});
+			shutdownService.register(10, {
+				serviceClass: MockComponent as unknown as ServiceClass,
+				methodName: 'onShutdown',
+			});
+			shutdownService.shutdown();
+			await shutdownService.waitForShutdown();
+
+			expect(mockErrorReporterProxy).toHaveBeenCalledTimes(1);
+			const error = mockErrorReporterProxy.mock.calls[0][0];
+			expect(error).toBeInstanceOf(ApplicationError);
+			expect(error.message).toBe('Failed to shutdown gracefully');
+			expect(error.extra).toEqual({
+				component: 'MockComponent.onShutdown()',
+			});
+			expect(error.cause).toBe(componentError);
+		});
+	});
+
+	describe('waitForShutdown', () => {
+		it('should wait for shutdown', async () => {
+			shutdownService.register(10, {
+				serviceClass: MockComponent as unknown as ServiceClass,
+				methodName: 'onShutdown',
+			});
+			shutdownService.shutdown();
+			await expect(shutdownService.waitForShutdown()).resolves.toBeUndefined();
+		});
+
+		it('should throw error if app is not shutting down', async () => {
+			await expect(async () => shutdownService.waitForShutdown()).rejects.toThrow(
+				'App is not shutting down',
+			);
+		});
+	});
+
+	describe('isShuttingDown', () => {
+		it('should return true if app is shutting down', () => {
+			shutdownService.register(10, {
+				serviceClass: MockComponent as unknown as ServiceClass,
+				methodName: 'onShutdown',
+			});
+			shutdownService.shutdown();
+			expect(shutdownService.isShuttingDown()).toBe(true);
+		});
+
+		it('should return false if app is not shutting down', () => {
+			expect(shutdownService.isShuttingDown()).toBe(false);
+		});
+	});
+});