fix(cli): Fix issue with n8n crashing when error in poll method

packages/cli/src/ActiveWorkflowRunner.ts

@@ -32,6 +32,8 @@ import {
 	WorkflowActivationError,
 	WorkflowExecuteMode,
 	LoggerProxy as Logger,
+	WorkflowOperationError,
+	NodeApiError,
 } from 'n8n-workflow';
 
 import express from 'express';
@@ -51,6 +53,8 @@ import {
 	WorkflowHelpers,
 	WorkflowRunner,
 	ExternalHooks,
+	IExecutionDb,
+	IExecutionFlattedDb,
 } from '.';
 import config from '../config';
 import { User } from './databases/entities/User';
@@ -625,6 +629,83 @@ export class ActiveWorkflowRunner {
 		return workflowRunner.run(runData, true, undefined, undefined, responsePromise);
 	}
 
+	/**
+	 * Create an error execution
+	 *
+	 * @param {INode} node
+	 * @param {IWorkflowDb} workflowData
+	 * @param {Workflow} workflow
+	 * @param {WorkflowExecuteMode} mode
+	 * @returns
+	 * @memberof ActiveWorkflowRunner
+	 */
+	// eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
+	createErrorExecution(
+		error: ExecutionError,
+		node: INode,
+		workflowData: IWorkflowDb,
+		workflow: Workflow,
+		mode: WorkflowExecuteMode,
+	) {
+		const executionData: IRunExecutionData = {
+			startData: {
+				destinationNode: node.name,
+				runNodeFilter: [node.name],
+			},
+			executionData: {
+				contextData: {},
+				nodeExecutionStack: [
+					{
+						node,
+						data: {
+							main: [
+								[
+									{
+										json: {},
+										pairedItem: {
+											item: 0,
+										},
+									},
+								],
+							],
+						},
+						source: null,
+					},
+				],
+				waitingExecution: {},
+				waitingExecutionSource: {},
+			},
+			resultData: {
+				runData: {
+					[node.name]: [
+						{
+							startTime: 0,
+							executionTime: 0,
+							error,
+							source: [],
+						},
+					],
+				},
+				error,
+				lastNodeExecuted: node.name,
+			},
+		};
+
+		const fullExecutionData: IExecutionDb = {
+			data: executionData,
+			mode,
+			finished: false,
+			startedAt: new Date(),
+			workflowData,
+			workflowId: workflow.id,
+			stoppedAt: new Date(),
+		};
+
+		const execution = ResponseHelper.flattenExecutionData(fullExecutionData);
+
+		return Db.collections.Execution.save(execution as IExecutionFlattedDb);
+	}
+
 	/**
 	 * Return poll function which gets the global functions from n8n-core
 	 * and overwrites the __emit to be able to start it in subprocess
@@ -650,7 +731,14 @@ export class ActiveWorkflowRunner {
 				activation,
 			);
 			// eslint-disable-next-line no-underscore-dangle
-			returnFunctions.__emit = (data: INodeExecutionData[][]): void => {
+			returnFunctions.__emit = async (
+				data: INodeExecutionData[][] | ExecutionError,
+			): Promise<void> => {
+				if (data instanceof Error) {
+					await this.createErrorExecution(data, node, workflowData, workflow, mode);
+					this.executeErrorWorkflow(data, workflowData, mode);
+					return;
+				}
 				// eslint-disable-next-line @typescript-eslint/restrict-template-expressions
 				Logger.debug(`Received event to trigger execution for workflow "${workflow.name}"`);
 				WorkflowHelpers.saveStaticData(workflow);

packages/core/src/ActiveWorkflows.ts

@@ -18,6 +18,8 @@ import {
 	WorkflowActivateMode,
 	WorkflowActivationError,
 	WorkflowExecuteMode,
+	WorkflowOperationError,
+	NodeApiError,
 } from 'n8n-workflow';
 
 // eslint-disable-next-line import/no-cycle
@@ -163,24 +165,35 @@ export class ActiveWorkflows {
 
 		// Get all the trigger times
 		const cronTimes = (pollTimes.item || []).map(toCronExpression);
-
 		// The trigger function to execute when the cron-time got reached
-		const executeTrigger = async () => {
+		const executeTrigger = async (testingTrigger = false) => {
 			// eslint-disable-next-line @typescript-eslint/restrict-template-expressions
 			Logger.debug(`Polling trigger initiated for workflow "${workflow.name}"`, {
 				workflowName: workflow.name,
 				workflowId: workflow.id,
 			});
-			const pollResponse = await workflow.runPoll(node, pollFunctions);
 
-			if (pollResponse !== null) {
-				// eslint-disable-next-line no-underscore-dangle
-				pollFunctions.__emit(pollResponse);
+			try {
+				const pollResponse = await workflow.runPoll(node, pollFunctions);
+
+				if (pollResponse !== null) {
+					// eslint-disable-next-line no-underscore-dangle
+					pollFunctions.__emit(pollResponse);
+				}
+			} catch (error) {
+				// If the poll function failes in the first activation
+				// throw the error back so we let the user know there is
+				// an issue with the trigger.
+				if (testingTrigger) {
+					throw error;
+				}
+				// eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, no-underscore-dangle
+				pollFunctions.__emit(error);
 			}
 		};
 
 		// Execute the trigger directly to be able to know if it works
-		await executeTrigger();
+		await executeTrigger(true);
 
 		const timezone = pollFunctions.getTimezone();
 

packages/workflow/src/Interfaces.ts

@@ -716,7 +716,7 @@ export interface IHookFunctions {
 }
 
 export interface IPollFunctions {
-	__emit(data: INodeExecutionData[][]): void;
+	__emit(data: INodeExecutionData[][] | NodeApiError): void;
 	getCredentials(type: string): Promise<ICredentialDataDecryptedObject>;
 	getMode(): WorkflowExecuteMode;
 	getActivationMode(): WorkflowActivateMode;