From 2ca4e55502e03985d2c9b1b0033b6f5151ccb8f4 Mon Sep 17 00:00:00 2001
From: Anne Aguirre <anne.aguirre@n8n.io>
Date: Mon, 12 Oct 2026 21:18:01 +0000
Subject: [PATCH] fix(core): Stabilise background child approval wait (#40834)

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>
---
 .../agent-execution.repository.test.ts        | 71 +++++++++++++------
 1 file changed, 50 insertions(+), 21 deletions(-)

diff --git a/packages/cli/test/integration/database/repositories/agent-execution.repository.test.ts b/packages/cli/test/integration/database/repositories/agent-execution.repository.test.ts
index c6141927ea9..303dacb67da 100644
--- a/packages/cli/test/integration/database/repositories/agent-execution.repository.test.ts
+++ b/packages/cli/test/integration/database/repositories/agent-execution.repository.test.ts
@@ -380,7 +380,9 @@ describe('AgentExecutionRepository', () => {
 		});
 	}
 
-	describe('background child approvals', () => {
+	describe('background child approvals', { timeout: 20_000 }, () => {
+		const childSettleTimeoutMs = 8_000;
+
 		afterEach(async () => {
 			vi.restoreAllMocks();
 			await Container.get(AgentBackgroundJobRepository).delete({});
@@ -446,10 +448,6 @@ describe('AgentExecutionRepository', () => {
 				},
 			);
 			const wake = mock<AgentWakeService>();
-			const initialSuspensionPersisted = createDeferredPromise();
-			wake.requestWake.mockImplementation(async () => {
-				initialSuspensionPersisted.resolve();
-			});
 			const getService = Container.get.bind(Container);
 			vi.spyOn(Container, 'get').mockImplementation((service) => {
 				if (service === AgentRuntimeReconstructionService) return reconstruction;
@@ -530,8 +528,32 @@ describe('AgentExecutionRepository', () => {
 				if (!approval) throw new Error('Expected a pending approval');
 				return { job, approval };
 			};
-			await vi.waitFor(() => expect(wake.requestWake).toHaveBeenCalledWith(parent.id));
-			await initialSuspensionPersisted.promise;
+			// spawn returns before the child suspends. Read the job row before the
+			// wake assertion so a failed child is distinct from a late wake.
+			const deadline = Date.now() + childSettleTimeoutMs;
+			let suspendedJob = await jobs.findById(receipt.jobId);
+			while (suspendedJob?.status === 'running' && Date.now() < deadline) {
+				await new Promise((resolve) => setTimeout(resolve, 50));
+				suspendedJob = await jobs.findById(receipt.jobId);
+			}
+			const jobState = [
+				`status=${suspendedJob?.status ?? 'missing'}`,
+				`error=${suspendedJob?.error ?? 'null'}`,
+			].join(', ');
+			if (!suspendedJob || suspendedJob.status !== 'suspended' || suspendedJob.error !== null) {
+				throw new Error(`Background child did not suspend (${jobState})`);
+			}
+			try {
+				await vi.waitFor(() => expect(wake.requestWake).toHaveBeenCalledWith(parent.id), {
+					timeout: childSettleTimeoutMs,
+					interval: 50,
+				});
+			} catch (error) {
+				throw new Error(
+					`Background child is suspended but requestWake was not called for ${parent.id}`,
+					{ cause: error },
+				);
+			}
 			expect(await jobs.findById(receipt.jobId)).toMatchObject({
 				status: 'suspended',
 				error: null,
@@ -580,11 +602,13 @@ describe('AgentExecutionRepository', () => {
 					{ token: approval.token, resumeData: { approved } },
 					context,
 				);
-				await vi.waitFor(async () =>
-					expect(await jobs.findById(job.id)).toMatchObject({
-						status: 'completed',
-						childThreadId: job.childThreadId,
-					}),
+				await vi.waitFor(
+					async () =>
+						expect(await jobs.findById(job.id)).toMatchObject({
+							status: 'completed',
+							childThreadId: job.childThreadId,
+						}),
+					{ timeout: childSettleTimeoutMs },
 				);
 				expect(fixture.action).toHaveBeenCalledTimes(approved ? 1 : 0);
 				expect(fixture.workspaceService.getAgentWorkspace).toHaveBeenCalledWith(
@@ -621,11 +645,14 @@ describe('AgentExecutionRepository', () => {
 					.runner.resume(job, { token: approval.token, resumeData: { approved: true } }, context),
 			]);
 			expect(outcomes.map(({ status }) => status).sort()).toEqual(['fulfilled', 'rejected']);
-			await vi.waitFor(async () => {
-				const current = await fixture.readApproval();
-				expect(current.job.status).toBe('suspended');
-				expect(current.approval.token).not.toBe(approval.token);
-			});
+			await vi.waitFor(
+				async () => {
+					const current = await fixture.readApproval();
+					expect(current.job.status).toBe('suspended');
+					expect(current.approval.token).not.toBe(approval.token);
+				},
+				{ timeout: childSettleTimeoutMs },
+			);
 			const next = await fixture.readApproval();
 			expect(
 				await fixture.service.settle(
@@ -649,8 +676,9 @@ describe('AgentExecutionRepository', () => {
 				{ token: next.approval.token, resumeData: { approved: true } },
 				context,
 			);
-			await vi.waitFor(async () =>
-				expect(await jobs.findById(job.id)).toMatchObject({ status: 'completed' }),
+			await vi.waitFor(
+				async () => expect(await jobs.findById(job.id)).toMatchObject({ status: 'completed' }),
+				{ timeout: childSettleTimeoutMs },
 			);
 			expect(fixture.action).toHaveBeenCalledTimes(2);
 		});
@@ -682,8 +710,9 @@ describe('AgentExecutionRepository', () => {
 				{ token: retry.approval.token, resumeData: { approved: true } },
 				context,
 			);
-			await vi.waitFor(async () =>
-				expect(await jobs.findById(job.id)).toMatchObject({ status: 'completed' }),
+			await vi.waitFor(
+				async () => expect(await jobs.findById(job.id)).toMatchObject({ status: 'completed' }),
+				{ timeout: childSettleTimeoutMs },
 			);
 			expect(action).toHaveBeenCalledOnce();
 		});