fix(core): Add check that queue is defined and remove cyclic dependency (#7404)

In a rare edge case an undefined queue could be returned - this should
not happen and now an error is thrown.
Also using the opportunity to remove a cyclic dependency from the Queue.

packages/cli/src/Queue.ts

@@ -2,7 +2,8 @@ import type Bull from 'bull';
 import { Service } from 'typedi';
 import type { ExecutionError, IExecuteResponsePromiseData } from 'n8n-workflow';
 import { ActiveExecutions } from '@/ActiveExecutions';
-import * as WebhookHelpers from '@/WebhookHelpers';
+import { decodeWebhookResponse } from '@/helpers/decodeWebhookResponse';
+
 import {
 	getRedisClusterClient,
 	getRedisClusterNodes,
@@ -62,7 +63,7 @@ export class Queue {
 		this.jobQueue.on('global:progress', (jobId, progress: WebhookResponse) => {
 			this.activeExecutions.resolveResponsePromise(
 				progress.executionId,
-				WebhookHelpers.decodeWebhookResponse(progress.response),
+				decodeWebhookResponse(progress.response),
 			);
 		});
 	}
@@ -79,7 +80,23 @@ export class Queue {
 		return this.jobQueue.getJobs(jobTypes);
 	}
 
+	async process(concurrency: number, fn: Bull.ProcessCallbackFunction<JobData>): Promise<void> {
+		return this.jobQueue.process(concurrency, fn);
+	}
+
+	async ping(): Promise<string> {
+		return this.jobQueue.client.ping();
+	}
+
+	async pause(isLocal?: boolean): Promise<void> {
+		return this.jobQueue.pause(isLocal);
+	}
+
 	getBullObjectInstance(): JobQueue {
+		if (this.jobQueue === undefined) {
+			// if queue is not initialized yet throw an error, since we do not want to hand around an undefined queue
+			throw new Error('Queue is not initialized yet!');
+		}
 		return this.jobQueue;
 	}
 

packages/cli/src/WebhookHelpers.ts

@@ -160,23 +160,6 @@ export function getWorkflowWebhooks(
 	return returnData;
 }
 
-export function decodeWebhookResponse(
-	response: IExecuteResponsePromiseData,
-): IExecuteResponsePromiseData {
-	if (
-		typeof response === 'object' &&
-		typeof response.body === 'object' &&
-		(response.body as IDataObject)['__@N8nEncodedBuffer@__']
-	) {
-		response.body = Buffer.from(
-			(response.body as IDataObject)['__@N8nEncodedBuffer@__'] as string,
-			BINARY_ENCODING,
-		);
-	}
-
-	return response;
-}
-
 export function encodeWebhookResponse(
 	response: IExecuteResponsePromiseData,
 ): IExecuteResponsePromiseData {

packages/cli/src/WorkflowRunner.ts

@@ -37,10 +37,10 @@ import type {
 	IWorkflowExecutionDataProcessWithExecution,
 } from '@/Interfaces';
 import { NodeTypes } from '@/NodeTypes';
-import type { Job, JobData, JobQueue, JobResponse } from '@/Queue';
+import type { Job, JobData, JobResponse } from '@/Queue';
 // eslint-disable-next-line import/no-cycle
 import { Queue } from '@/Queue';
-import * as WebhookHelpers from '@/WebhookHelpers';
+import { decodeWebhookResponse } from '@/helpers/decodeWebhookResponse';
 // eslint-disable-next-line import/no-cycle
 import * as WorkflowHelpers from '@/WorkflowHelpers';
 // eslint-disable-next-line import/no-cycle
@@ -60,7 +60,7 @@ export class WorkflowRunner {
 
 	push: Push;
 
-	jobQueue: JobQueue;
+	jobQueue: Queue;
 
 	constructor() {
 		this.push = Container.get(Push);
@@ -172,8 +172,7 @@ export class WorkflowRunner {
 		await initErrorHandling();
 
 		if (executionsMode === 'queue') {
-			const queue = Container.get(Queue);
+			this.jobQueue = Container.get(Queue);
-			this.jobQueue = queue.getBullObjectInstance();
 		}
 
 		if (executionsMode === 'queue' && data.executionMode !== 'manual') {
@@ -733,7 +732,7 @@ export class WorkflowRunner {
 				this.activeExecutions.remove(executionId, message.data.runData);
 			} else if (message.type === 'sendResponse') {
 				if (responsePromise) {
-					responsePromise.resolve(WebhookHelpers.decodeWebhookResponse(message.data.response));
+					responsePromise.resolve(decodeWebhookResponse(message.data.response));
 				}
 			} else if (message.type === 'sendDataToUI') {
 				// eslint-disable-next-line @typescript-eslint/no-unsafe-call

packages/cli/src/commands/worker.ts

@@ -22,7 +22,7 @@ import * as WorkflowExecuteAdditionalData from '@/WorkflowExecuteAdditionalData'
 import { PermissionChecker } from '@/UserManagement/PermissionChecker';
 
 import config from '@/config';
-import type { Job, JobId, JobQueue, JobResponse, WebhookResponse } from '@/Queue';
+import type { Job, JobId, JobResponse, WebhookResponse } from '@/Queue';
 import { Queue } from '@/Queue';
 import { generateFailedExecutionFromError } from '@/WorkflowHelpers';
 import { N8N_VERSION } from '@/constants';
@@ -61,7 +61,7 @@ export class Worker extends BaseCommand {
 		[jobId: string]: WorkerJobStatusSummary;
 	} = {};
 
-	static jobQueue: JobQueue;
+	static jobQueue: Queue;
 
 	redisSubscriber: RedisServicePubSubSubscriber;
 
@@ -335,15 +335,14 @@ export class Worker extends BaseCommand {
 			`Opening Redis connection to listen to messages with timeout ${redisConnectionTimeoutLimit}`,
 		);
 
-		const queue = Container.get(Queue);
+		Worker.jobQueue = Container.get(Queue);
-		await queue.init();
+		await Worker.jobQueue.init();
 		this.logger.debug('Queue singleton ready');
-		Worker.jobQueue = queue.getBullObjectInstance();
 		void Worker.jobQueue.process(flags.concurrency, async (job) =>
 			this.runJob(job, this.nodeTypes),
 		);
 
-		Worker.jobQueue.on('global:progress', (jobId: JobId, progress) => {
+		Worker.jobQueue.getBullObjectInstance().on('global:progress', (jobId: JobId, progress) => {
 			// Progress of a job got updated which does get used
 			// to communicate that a job got canceled.
 
@@ -359,7 +358,7 @@ export class Worker extends BaseCommand {
 
 		let lastTimer = 0;
 		let cumulativeTimeout = 0;
-		Worker.jobQueue.on('error', (error: Error) => {
+		Worker.jobQueue.getBullObjectInstance().on('error', (error: Error) => {
 			if (error.toString().includes('ECONNREFUSED')) {
 				const now = Date.now();
 				if (now - lastTimer > 30000) {
@@ -423,7 +422,7 @@ export class Worker extends BaseCommand {
 				// if it loses the connection to redis
 				try {
 					// Redis ping
-					await Worker.jobQueue.client.ping();
+					await Worker.jobQueue.ping();
 				} catch (e) {
 					LoggerProxy.error('No Redis connection!', e as Error);
 					const error = new ResponseHelper.ServiceUnavailableError('No Redis connection!');

packages/cli/src/helpers/decodeWebhookResponse.ts

@@ -0,0 +1,18 @@
+import { BINARY_ENCODING, type IDataObject, type IExecuteResponsePromiseData } from 'n8n-workflow';
+
+export function decodeWebhookResponse(
+	response: IExecuteResponsePromiseData,
+): IExecuteResponsePromiseData {
+	if (
+		typeof response === 'object' &&
+		typeof response.body === 'object' &&
+		(response.body as IDataObject)['__@N8nEncodedBuffer@__']
+	) {
+		response.body = Buffer.from(
+			(response.body as IDataObject)['__@N8nEncodedBuffer@__'] as string,
+			BINARY_ENCODING,
+		);
+	}
+
+	return response;
+}