feat(core): Cancel runner task on timeout in external mode (#12101)

packages/@n8n/task-runner/src/js-task-runner/errors/timeout-error.ts

@@ -0,0 +1,30 @@
+import { ApplicationError } from 'n8n-workflow';
+
+export class TimeoutError extends ApplicationError {
+	description: string;
+
+	constructor(taskTimeout: number) {
+		super(
+			`Task execution timed out after ${taskTimeout} ${taskTimeout === 1 ? 'second' : 'seconds'}`,
+		);
+
+		const subtitle = 'The task runner was taking too long on this task, so the task was aborted.';
+
+		const fixes = {
+			optimizeScript:
+				'Optimize your script to prevent long-running tasks, e.g. by processing data in smaller batches.',
+			ensureTermination:
+				'Ensure that all paths in your script are able to terminate, i.e. no infinite loops.',
+		};
+
+		const suggestions = [fixes.optimizeScript, fixes.ensureTermination];
+
+		const suggestionsText = suggestions
+			.map((suggestion, index) => `${index + 1}. ${suggestion}`)
+			.join('<br/>');
+
+		const description = `${subtitle} You can try the following:<br/><br/>${suggestionsText}`;
+
+		this.description = description;
+	}
+}