feat(core): Validate shutdown handlers on startup (#8260)

packages/cli/src/commands/BaseCommand.ts

@@ -9,7 +9,7 @@ import { Logger } from '@/Logger';
 import config from '@/config';
 import * as Db from '@/Db';
 import * as CrashJournal from '@/CrashJournal';
-import { LICENSE_FEATURES, inTest } from '@/constants';
+import { LICENSE_FEATURES, inDevelopment, inTest } from '@/constants';
 import { initErrorHandling } from '@/ErrorReporting';
 import { ExternalHooks } from '@/ExternalHooks';
 import { NodeTypes } from '@/NodeTypes';
@@ -63,6 +63,12 @@ export abstract class BaseCommand extends Command {
 			this.exitWithCrash('There was an error initializing DB', error),
 		);
 
+		// This needs to happen after DB.init() or otherwise DB Connection is not
+		// available via the dependency Container that services depend on.
+		if (inDevelopment || inTest) {
+			this.shutdownService.validate();
+		}
+
 		await this.server?.init();
 
 		await Db.migrate().catch(async (error: Error) =>

packages/cli/src/shutdown/Shutdown.service.ts

@@ -39,6 +39,26 @@ export class ShutdownService {
 		this.handlersByPriority[priority].push(handler);
 	}
 
+	/** Validates that all the registered shutdown handlers are properly configured */
+	validate() {
+		const handlers = this.handlersByPriority.flat();
+
+		for (const { serviceClass, methodName } of handlers) {
+			if (!Container.has(serviceClass)) {
+				throw new ApplicationError(
+					`Component "${serviceClass.name}" is not registered with the DI container. Any component using @OnShutdown() must be decorated with @Service()`,
+				);
+			}
+
+			const service = Container.get(serviceClass);
+			if (!service[methodName]) {
+				throw new ApplicationError(
+					`Component "${serviceClass.name}" does not have a "${methodName}" method`,
+				);
+			}
+		}
+	}
+
 	/** Signals all registered listeners that the application is shutting down */
 	shutdown() {
 		if (this.shutdownPromise) {