Add Webhook response node (#2254)

* ✨ Add Webhook-Response-Node

* ⚡ Replace callback function with promise

* ✨ Add support for Bull and binary-data

* ✨ Add string response option

* ⚡ Remove some comments

* ✨ Make more generically possible & fix issue multi call in
queue mode

* ⚡ Fix startup and eslint issues

* ⚡ Improvements to webhook response node and functionality

* ⚡ Replace data with more generic type

* ⚡ Make statusMessage optional

* ⚡ Change parameter order

* ⚡ Move Response Code underneath options

* ⚡ Hide Response Code on Webhook node if mode responseNode got selected

* ⚡ Minor improvements

* ⚡ Add missing file and fix lint issue

* ⚡ Fix some node linting issues

* ⚡ Apply feedback

* ⚡ Minor improvements

packages/workflow/src/DeferredPromise.ts

@@ -0,0 +1,14 @@
+// From: https://gist.github.com/compulim/8b49b0a744a3eeb2205e2b9506201e50
+export interface IDeferredPromise<T> {
+	promise: () => Promise<T>;
+	reject: (error: Error) => void;
+	resolve: (result: T) => void;
+}
+
+export async function createDeferredPromise<T>(): Promise<IDeferredPromise<T>> {
+	return new Promise<IDeferredPromise<T>>((resolveCreate) => {
+		const promise = new Promise<T>((resolve, reject) => {
+			resolveCreate({ promise: async () => promise, resolve, reject });
+		});
+	});
+}

packages/workflow/src/Interfaces.ts

@@ -6,6 +6,7 @@
 import * as express from 'express';
 import * as FormData from 'form-data';
 import { URLSearchParams } from 'url';
+import { IDeferredPromise } from './DeferredPromise';
 import { Workflow } from './Workflow';
 import { WorkflowHooks } from './WorkflowHooks';
 import { WorkflowOperationError } from './WorkflowErrors';
@@ -208,6 +209,9 @@ export interface IDataObject {
 	[key: string]: GenericValue | IDataObject | GenericValue[] | IDataObject[];
 }
 
+// export type IExecuteResponsePromiseData = IDataObject;
+export type IExecuteResponsePromiseData = IDataObject | IN8nHttpFullResponse;
+
 export interface INodeTypeNameVersion {
 	name: string;
 	version: number;
@@ -324,13 +328,13 @@ export interface IHttpRequestOptions {
 	json?: boolean;
 }
 
-export type IN8nHttpResponse = IDataObject | Buffer | GenericValue | GenericValue[];
+export type IN8nHttpResponse = IDataObject | Buffer | GenericValue | GenericValue[] | null;
 
 export interface IN8nHttpFullResponse {
 	body: IN8nHttpResponse;
 	headers: IDataObject;
 	statusCode: number;
-	statusMessage: string;
+	statusMessage?: string;
 }
 
 export interface IExecuteFunctions {
@@ -371,7 +375,8 @@ export interface IExecuteFunctions {
 		outputIndex?: number,
 	): Promise<INodeExecutionData[][]>;
 	putExecutionToWait(waitTill: Date): Promise<void>;
-	sendMessageToUI(message: any): void;
+	sendMessageToUI(message: any): void; // tslint:disable-line:no-any
+	sendResponse(response: IExecuteResponsePromiseData): void; // tslint:disable-line:no-any
 	helpers: {
 		httpRequest(
 			requestOptions: IHttpRequestOptions,
@@ -492,7 +497,10 @@ export interface IPollFunctions {
 }
 
 export interface ITriggerFunctions {
-	emit(data: INodeExecutionData[][]): void;
+	emit(
+		data: INodeExecutionData[][],
+		responsePromise?: IDeferredPromise<IExecuteResponsePromiseData>,
+	): void;
 	getCredentials(type: string): Promise<ICredentialDataDecryptedObject | undefined>;
 	getMode(): WorkflowExecuteMode;
 	getActivationMode(): WorkflowActivateMode;
@@ -975,6 +983,7 @@ export interface IWorkflowExecuteHooks {
 	nodeExecuteBefore?: Array<(nodeName: string) => Promise<void>>;
 	workflowExecuteAfter?: Array<(data: IRun, newStaticData: IDataObject) => Promise<void>>;
 	workflowExecuteBefore?: Array<(workflow: Workflow, data: IRunExecutionData) => Promise<void>>;
+	sendResponse?: Array<(response: IExecuteResponsePromiseData) => Promise<void>>;
 }
 
 export interface IWorkflowExecuteAdditionalData {

packages/workflow/src/Workflow.ts

@@ -16,6 +16,8 @@
 import {
 	Expression,
 	IConnections,
+	IDeferredPromise,
+	IExecuteResponsePromiseData,
 	IGetExecuteTriggerFunctions,
 	INode,
 	INodeExecuteFunctions,
@@ -946,10 +948,23 @@ export class Workflow {
 
 			// Add the manual trigger response which resolves when the first time data got emitted
 			triggerResponse!.manualTriggerResponse = new Promise((resolve) => {
-				// eslint-disable-next-line @typescript-eslint/no-shadow
-				triggerFunctions.emit = ((resolve) => (data: INodeExecutionData[][]) => {
-					resolve(data);
-				})(resolve);
+				triggerFunctions.emit = (
+					(resolveEmit) =>
+					(
+						data: INodeExecutionData[][],
+						responsePromise?: IDeferredPromise<IExecuteResponsePromiseData>,
+					) => {
+						additionalData.hooks!.hookFunctions.sendResponse = [
+							async (response: IExecuteResponsePromiseData): Promise<void> => {
+								if (responsePromise) {
+									responsePromise.resolve(response);
+								}
+							},
+						];
+
+						resolveEmit(data);
+					}
+				)(resolve);
 			});
 
 			return triggerResponse;

packages/workflow/src/index.ts

@@ -3,6 +3,7 @@ import * as LoggerProxy from './LoggerProxy';
 import * as NodeHelpers from './NodeHelpers';
 import * as ObservableObject from './ObservableObject';
 
+export * from './DeferredPromise';
 export * from './Interfaces';
 export * from './Expression';
 export * from './NodeErrors';