refactor(core): Lint to enforce lazyloading in modules (#16843)

Co-authored-by: Juuso Tapaninen <juuso@n8n.io>

packages/cli/eslint.config.mjs

@@ -99,4 +99,12 @@ export default defineConfig(
 			'n8n-local-rules/no-uncaught-json-parse': 'warn',
 		},
 	},
+	{
+		files: ['**/*.module.ts'],
+
+		rules: {
+			'n8n-local-rules/no-top-level-relative-imports-in-backend-module': 'error',
+			'n8n-local-rules/no-constructor-in-backend-module': 'error',
+		},
+	},
 );

packages/cli/src/modules/insights/insights.module.ts

@@ -1,23 +1,16 @@
 import type { ModuleInterface } from '@n8n/decorators';
 import { BackendModule } from '@n8n/decorators';
 import { Container } from '@n8n/di';
-import './insights.controller';
 import { InstanceSettings } from 'n8n-core';
 
-import { InsightsByPeriod } from './database/entities/insights-by-period';
-import { InsightsMetadata } from './database/entities/insights-metadata';
-import { InsightsRaw } from './database/entities/insights-raw';
-
 @BackendModule({ name: 'insights' })
 export class InsightsModule implements ModuleInterface {
 	async init() {
-		const { instanceType } = Container.get(InstanceSettings);
-
 		/**
 		 * Only main- and webhook-type instances collect insights because
 		 * only they are informed of finished workflow executions.
 		 */
-		if (instanceType === 'worker') return;
+		if (Container.get(InstanceSettings).instanceType === 'worker') return;
 
 		await import('./insights.controller');
 
@@ -25,12 +18,17 @@ export class InsightsModule implements ModuleInterface {
 		Container.get(InsightsService).startTimers();
 	}
 
-	entities() {
+	async entities() {
+		const { InsightsByPeriod } = await import('./database/entities/insights-by-period');
+		const { InsightsMetadata } = await import('./database/entities/insights-metadata');
+		const { InsightsRaw } = await import('./database/entities/insights-raw');
+
 		return [InsightsByPeriod, InsightsMetadata, InsightsRaw];
 	}
 
 	async settings() {
 		const { InsightsService } = await import('./insights.service');
+
 		return Container.get(InsightsService).settings();
 	}
 }