fix(Execute Workflow Node): Fix 'Continue (using error output)' mode to output errors correctly (#19240)

packages/nodes-base/nodes/ExecuteWorkflow/ExecuteWorkflow/ExecuteWorkflow.node.test.ts

@@ -1,5 +1,5 @@
 import { mock } from 'jest-mock-extended';
-import type { IExecuteFunctions, IWorkflowDataProxyData } from 'n8n-workflow';
+import type { IExecuteFunctions, IWorkflowDataProxyData, INode } from 'n8n-workflow';
 
 import { ExecuteWorkflow } from './ExecuteWorkflow.node';
 import { getWorkflowInfo } from './GenericFunctions';
@@ -81,13 +81,15 @@ describe('ExecuteWorkflow', () => {
 		expect(result).toEqual([[{ json: { key: 'value' }, index: 0, pairedItem: { item: 0 } }]]);
 	});
 
-	test('should handle errors and continue on fail', async () => {
+	test('should handle errors and continue on fail, no items, < 1.3 version', async () => {
 		executeFunctions.getNodeParameter
 			.mockReturnValueOnce('database') // source
 			.mockReturnValueOnce('each') // mode
 			.mockReturnValueOnce(true) // waitForSubWorkflow
 			.mockReturnValueOnce([]); // workflowInputs.schema
 
+		executeFunctions.getNode.mockReturnValue({ typeVersion: 1.2 } as INode);
+
 		(getWorkflowInfo as jest.Mock).mockRejectedValue(new Error('Test error'));
 		(executeFunctions.continueOnFail as jest.Mock).mockReturnValue(true);
 
@@ -96,6 +98,77 @@ describe('ExecuteWorkflow', () => {
 		expect(result).toEqual([[{ json: { error: 'Test error' }, pairedItem: { item: 0 } }]]);
 	});
 
+	test('should handle errors and continue on fail, multiple items, < 1.3 version', async () => {
+		executeFunctions.getNodeParameter
+			.mockReturnValueOnce('database') // source
+			.mockReturnValueOnce('each') // mode
+			.mockReturnValueOnce(true) // waitForSubWorkflow
+			.mockReturnValue([]); // workflowInputs.schema
+
+		executeFunctions.getNode.mockReturnValue({ typeVersion: 1.2 } as INode);
+		executeFunctions.getInputData.mockReturnValueOnce([
+			{ json: { key: '1' } },
+			{ json: { key: '2' } },
+			{ json: { key: '3' } },
+		]);
+
+		(getWorkflowInfo as jest.Mock).mockRejectedValue(new Error('Test error'));
+		(executeFunctions.continueOnFail as jest.Mock).mockReturnValue(true);
+
+		const result = await executeWorkflow.execute.call(executeFunctions);
+
+		expect(result).toEqual([
+			[{ json: { error: 'Test error' }, pairedItem: { item: 0 }, metadata: undefined }],
+			[{ json: { error: 'Test error' }, pairedItem: { item: 1 }, metadata: undefined }],
+			[{ json: { error: 'Test error' }, pairedItem: { item: 2 }, metadata: undefined }],
+		]);
+	});
+
+	test('should handle errors and continue on fail, no items, >= 1.3 version', async () => {
+		executeFunctions.getNodeParameter
+			.mockReturnValueOnce('database') // source
+			.mockReturnValueOnce('each') // mode
+			.mockReturnValueOnce(true) // waitForSubWorkflow
+			.mockReturnValueOnce([]); // workflowInputs.schema
+
+		executeFunctions.getNode.mockReturnValue({ typeVersion: 1.3 } as INode);
+
+		(getWorkflowInfo as jest.Mock).mockRejectedValue(new Error('Test error'));
+		(executeFunctions.continueOnFail as jest.Mock).mockReturnValue(true);
+
+		const result = await executeWorkflow.execute.call(executeFunctions);
+
+		expect(result).toEqual([[{ json: { error: 'Test error' }, pairedItem: { item: 0 } }]]);
+	});
+
+	test('should handle errors and continue on fail, multiple items, >= 1.3 version', async () => {
+		executeFunctions.getNodeParameter
+			.mockReturnValueOnce('database') // source
+			.mockReturnValueOnce('each') // mode
+			.mockReturnValueOnce(true) // waitForSubWorkflow
+			.mockReturnValueOnce([]); // workflowInputs.schema
+
+		executeFunctions.getNode.mockReturnValue({ typeVersion: 1.3 } as INode);
+		executeFunctions.getInputData.mockReturnValueOnce([
+			{ json: { key: '1' } },
+			{ json: { key: '2' } },
+			{ json: { key: '3' } },
+		]);
+
+		(getWorkflowInfo as jest.Mock).mockRejectedValue(new Error('Test error'));
+		(executeFunctions.continueOnFail as jest.Mock).mockReturnValue(true);
+
+		const result = await executeWorkflow.execute.call(executeFunctions);
+
+		expect(result).toEqual([
+			[
+				{ json: { error: 'Test error' }, pairedItem: { item: 0 }, metadata: undefined },
+				{ json: { error: 'Test error' }, pairedItem: { item: 1 }, metadata: undefined },
+				{ json: { error: 'Test error' }, pairedItem: { item: 2 }, metadata: undefined },
+			],
+		]);
+	});
+
 	test('should throw error if not continuing on fail', async () => {
 		executeFunctions.getNodeParameter
 			.mockReturnValueOnce('database') // source

packages/nodes-base/nodes/ExecuteWorkflow/ExecuteWorkflow/ExecuteWorkflow.node.ts

@@ -20,7 +20,7 @@ export class ExecuteWorkflow implements INodeType {
 		icon: 'fa:sign-in-alt',
 		iconColor: 'orange-red',
 		group: ['transform'],
-		version: [1, 1.1, 1.2],
+		version: [1, 1.1, 1.2, 1.3],
 		subtitle: '={{"Workflow: " + $parameter["workflowId"]}}',
 		description: 'Execute another workflow',
 		defaults: {
@@ -369,11 +369,16 @@ export class ExecuteWorkflow implements INodeType {
 					}
 				} catch (error) {
 					if (this.continueOnFail()) {
-						if (returnData[i] === undefined) {
+						const nodeVersion = this.getNode().typeVersion;
-							returnData[i] = [];
+						// In versions < 1.3 using the "Continue (using error output)" mode
-						}
+						// the node would return items in extra "error branches" instead of
+						// returning an array of items on the error output. These branches weren't really shown correctly on the UI.
+						// In the fixed >= 1.3 versions the errors are now all output into the single error output as an array of error items.
+						const outputIndex = nodeVersion >= 1.3 ? 0 : i;
+
+						returnData[outputIndex] ??= [];
 						const metadata = parseErrorMetadata(error);
-						returnData[i].push({
+						returnData[outputIndex].push({
 							json: { error: error.message },
 							pairedItem: { item: i },
 							metadata,