feat(core): Node hints(warnings) system

packages/core/src/WorkflowExecute.ts

@@ -34,13 +34,15 @@ import type {
 	WorkflowExecuteMode,
 	CloseFunction,
 	StartNodeData,
+	NodeExecutionHint,
 } from 'n8n-workflow';
 import {
 	LoggerProxy as Logger,
 	WorkflowOperationError,
 	NodeHelpers,
 	NodeConnectionType,
 	ApplicationError,
+	NodeExecutionOutput,
 } from 'n8n-workflow';
 import get from 'lodash/get';
 import * as NodeExecuteFunctions from './NodeExecuteFunctions';
@@ -807,6 +809,7 @@ export class WorkflowExecute {
 		// Variables which hold temporary data for each node-execution
 		let executionData: IExecuteData;
 		let executionError: ExecutionBaseError | undefined;
+		let executionHints: NodeExecutionHint[] = [];
 		let executionNode: INode;
 		let nodeSuccessData: INodeExecutionData[][] | null | undefined;
 		let runIndex: number;
@@ -828,7 +831,7 @@ export class WorkflowExecute {
 		let lastExecutionTry = '';
 		let closeFunction: Promise<void> | undefined;
 
-		return new PCancelable(async (resolve, reject, onCancel) => {
+		return new PCancelable(async (resolve, _reject, onCancel) => {
 			// Let as many nodes listen to the abort signal, without getting the MaxListenersExceededWarning
 			setMaxListeners(Infinity, this.abortController.signal);
 
@@ -896,6 +899,7 @@ export class WorkflowExecute {
 
 					nodeSuccessData = null;
 					executionError = undefined;
+					executionHints = [];
 					executionData =
 						this.runExecutionData.executionData!.nodeExecutionStack.shift() as IExecuteData;
 					executionNode = executionData.node;
@@ -1059,8 +1063,16 @@ export class WorkflowExecute {
 									this.mode,
 									this.abortController.signal,
 								);
+
 								nodeSuccessData = runNodeData.data;
 
+								if (nodeSuccessData instanceof NodeExecutionOutput) {
+									// eslint-disable-next-line @typescript-eslint/no-unsafe-call
+									const hints: NodeExecutionHint[] = nodeSuccessData.getHints();
+									// eslint-disable-next-line @typescript-eslint/no-unsafe-argument
+									executionHints.push(...hints);
+								}
+
 								if (nodeSuccessData && executionData.node.onError === 'continueErrorOutput') {
 									// If errorOutput is activated check all the output items for error data.
 									// If any is found, route them to the last output as that will be the
@@ -1244,7 +1256,7 @@ export class WorkflowExecute {
 										if (!inputData) {
 											return;
 										}
-										inputData.forEach((item, itemIndex) => {
+										inputData.forEach((_item, itemIndex) => {
 											pairedItem.push({
 												item: itemIndex,
 												input: inputIndex,
@@ -1296,6 +1308,7 @@ export class WorkflowExecute {
 					}
 
 					taskData = {
+						hints: executionHints,
 						startTime,
 						executionTime: new Date().getTime() - startTime,
 						source: !executionData.source ? [] : executionData.source.main,

packages/core/test/WorkflowExecute.test.ts

@@ -1,5 +1,10 @@
 import type { IRun, WorkflowTestData } from 'n8n-workflow';
-import { ApplicationError, createDeferredPromise, Workflow } from 'n8n-workflow';
+import {
+	ApplicationError,
+	createDeferredPromise,
+	NodeExecutionOutput,
+	Workflow,
+} from 'n8n-workflow';
 import { WorkflowExecute } from '@/WorkflowExecute';
 
 import * as Helpers from './helpers';
@@ -192,4 +197,16 @@ describe('WorkflowExecute', () => {
 			});
 		}
 	});
+
+	describe('WorkflowExecute, NodeExecutionOutput type test', () => {
+		//TODO Add more tests here when execution hints are added to some node types
+		const nodeExecutionOutput = new NodeExecutionOutput(
+			[[{ json: { data: 123 } }]],
+			[{ message: 'TEXT HINT' }],
+		);
+
+		expect(nodeExecutionOutput).toBeInstanceOf(NodeExecutionOutput);
+		expect(nodeExecutionOutput[0][0].json.data).toEqual(123);
+		expect(nodeExecutionOutput.getHints()[0].message).toEqual('TEXT HINT');
+	});
 });

packages/editor-ui/src/components/RunData.vue

@@ -152,6 +152,15 @@
 		</div>
 		<slot name="before-data" />
 
+		<n8n-callout
+			v-for="hint in getNodeHints()"
+			:key="hint.message"
+			:class="$style.hintCallout"
+			:theme="hint.type || 'info'"
+		>
+			<n8n-text v-html="hint.message" size="small"></n8n-text>
+		</n8n-callout>
+
 		<div
 			v-if="maxOutputIndex > 0 && branches.length > 1"
 			:class="$style.tabs"
@@ -557,6 +566,7 @@ import type {
 	INodeTypeDescription,
 	IRunData,
 	IRunExecutionData,
+	NodeHint,
 } from 'n8n-workflow';
 import { NodeHelpers, NodeConnectionType } from 'n8n-workflow';
 
@@ -824,6 +834,15 @@ export default defineComponent({
 		hasRunError(): boolean {
 			return Boolean(this.node && this.workflowRunData?.[this.node.name]?.[this.runIndex]?.error);
 		},
+		executionHints(): NodeHint[] {
+			if (this.hasNodeRun) {
+				const hints = this.node && this.workflowRunData?.[this.node.name]?.[this.runIndex]?.hints;
+
+				if (hints) return hints;
+			}
+
+			return [];
+		},
 		workflowExecution(): IExecutionResponse | null {
 			return this.workflowsStore.getWorkflowExecution;
 		},
@@ -1083,6 +1102,46 @@ export default defineComponent({
 			}
 			return [];
 		},
+		shouldHintBeDisplayed(hint: NodeHint): boolean {
+			const { location, whenToDisplay } = hint;
+			if (location) {
+				if (location === 'ndv') {
+					return true;
+				}
+				if (location === 'inputPane' && this.paneType === 'input') {
+					return true;
+				}
+
+				if (location === 'outputPane' && this.paneType === 'output') {
+					return true;
+				}
+
+				return false;
+			}
+
+			if (whenToDisplay === 'afterExecution' && !this.hasNodeRun) {
+				return false;
+			}
+
+			if (whenToDisplay === 'beforeExecution' && this.hasNodeRun) {
+				return false;
+			}
+
+			return true;
+		},
+		getNodeHints(): NodeHint[] {
+			if (this.node && this.nodeType) {
+				const workflow = this.workflowsStore.getCurrentWorkflow();
+				const workflowNode = workflow.getNode(this.node.name);
+
+				if (workflowNode) {
+					const executionHints = this.executionHints;
+					const nodeHints = NodeHelpers.getNodeHints(workflow, workflowNode, this.nodeType);
+					return executionHints.concat(nodeHints).filter(this.shouldHintBeDisplayed);
+				}
+			}
+			return [];
+		},
 		onItemHover(itemIndex: number | null) {
 			if (itemIndex === null) {
 				this.$emit('itemHover', null);
@@ -1788,6 +1847,12 @@ export default defineComponent({
 	border-top-left-radius: 0;
 	border-bottom-left-radius: 0;
 }
+
+.hintCallout {
+	margin-bottom: var(--spacing-xs);
+	margin-left: var(--spacing-s);
+	margin-right: var(--spacing-s);
+}
 </style>
 
 <style lang="scss" scoped>

packages/nodes-base/utils/constants.ts

@@ -0,0 +1,2 @@
+export const NODE_RAN_MULTIPLE_TIMES_WARNING =
+	"This node ran multiple times - once for each input item. You can change this by setting 'execute once' in the node settings. <a href='https://docs.n8n.io/flow-logic/looping/#executing-nodes-once' target='_blank'>More Info</a>";

packages/workflow/src/Interfaces.ts

@@ -392,7 +392,7 @@ export interface IGetExecuteTriggerFunctions {
 }
 
 export interface IRunNodeResponse {
-	data: INodeExecutionData[][] | null | undefined;
+	data: INodeExecutionData[][] | NodeExecutionOutput | null | undefined;
 	closeFunction?: CloseFunction;
 }
 export interface IGetExecuteFunctions {
@@ -1423,6 +1423,20 @@ export interface SupplyData {
 	closeFunction?: CloseFunction;
 }
 
+export class NodeExecutionOutput extends Array {
+	private hints: NodeExecutionHint[];
+
+	constructor(data: INodeExecutionData[][], hints: NodeExecutionHint[] = []) {
+		super();
+		this.push(...data);
+		this.hints = hints;
+	}
+
+	public getHints(): NodeExecutionHint[] {
+		return this.hints;
+	}
+}
+
 export interface INodeType {
 	description: INodeTypeDescription;
 	supplyData?(this: IAllExecuteFunctions, itemIndex: number): Promise<SupplyData>;
@@ -1745,9 +1759,20 @@ export interface INodeTypeDescription extends INodeTypeBaseDescription {
 		  }
 		| boolean;
 	extendsCredential?: string;
+	hints?: NodeHint[];
 	__loadOptionsMethods?: string[]; // only for validation during build
 }
 
+export type NodeHint = {
+	message: string;
+	type?: 'info' | 'warning' | 'danger';
+	location?: 'outputPane' | 'inputPane' | 'ndv';
+	displayCondition?: string;
+	whenToDisplay?: 'always' | 'beforeExecution' | 'afterExecution';
+};
+
+export type NodeExecutionHint = Omit<NodeHint, 'whenToDisplay' | 'displayCondition'>;
+
 export interface INodeHookDescription {
 	method: string;
 }
@@ -1929,6 +1954,7 @@ export interface ITaskData {
 	data?: ITaskDataConnections;
 	inputOverride?: ITaskDataConnections;
 	error?: ExecutionError;
+	hints?: NodeExecutionHint[];
 	source: Array<ISourceData | null>; // Is an array as nodes have multiple inputs
 	metadata?: ITaskMetadata;
 }

packages/workflow/src/NodeHelpers.ts

@@ -42,6 +42,7 @@ import type {
 	INodeInputConfiguration,
 	GenericValue,
 	DisplayCondition,
+	NodeHint,
 } from './Interfaces';
 import {
 	isFilterValue,
@@ -1120,6 +1121,50 @@ export function getNodeInputs(
 	}
 }
 
+export function getNodeHints(
+	workflow: Workflow,
+	node: INode,
+	nodeTypeData: INodeTypeDescription,
+): NodeHint[] {
+	const hints: NodeHint[] = [];
+
+	if (nodeTypeData?.hints?.length) {
+		for (const hint of nodeTypeData.hints) {
+			if (hint.displayCondition) {
+				try {
+					const display = (workflow.expression.getSimpleParameterValue(
+						node,
+						hint.displayCondition,
+						'internal',
+						{},
+					) || false) as boolean;
+
+					if (typeof display !== 'boolean') {
+						console.warn(
+							`Condition was not resolved as boolean in '${node.name}' node for hint: `,
+							hint.message,
+						);
+						continue;
+					}
+
+					if (display) {
+						hints.push(hint);
+					}
+				} catch (e) {
+					console.warn(
+						`Could not calculate display condition in '${node.name}' node for hint: `,
+						hint.message,
+					);
+				}
+			} else {
+				hints.push(hint);
+			}
+		}
+	}
+
+	return hints;
+}
+
 export function getNodeOutputs(
 	workflow: Workflow,
 	node: INode,