✨ OPTIONS request support for Production/Test Webhooks (#787)

* 🐛 Fix naming of events in AffinityTrigger Node

* 🚧 OPTIONS allow header response for production webhooks

* ✅ Implemented Allow header for test webhook OPTIONS response

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/cli/src/ActiveWorkflowRunner.ts

@@ -161,6 +161,24 @@ export class ActiveWorkflowRunner {
 		});
 	}
 
+/**
+ * Gets all request methods associated with a single webhook
+ * @param path webhook path
+ */
+	async getWebhookMethods(path: string) : Promise<string[]> {
+		const webhooks = await Db.collections.Webhook?.find({ webhookPath: path}) as IWebhookDb[];
+
+		// check if something exist
+		if (webhooks === undefined) {
+			// The requested webhooks are not registered
+			throw new ResponseHelper.ResponseError(`The requested webhook "${path}" is not registered.`, 404, 404);
+		}
+
+		// Gather all request methods in string array
+		let webhookMethods : string[] = webhooks.map(webhook => webhook.method);
+		return webhookMethods;
+	}
+
 	/**
 	 * Returns the ids of the currently active workflows
 	 *

packages/cli/src/Server.ts

@@ -1567,6 +1567,25 @@ class App {
 			ResponseHelper.sendSuccessResponse(res, response.data, true, response.responseCode);
 		});
 
+		// OPTIONS webhook requests
+		this.app.options(`/${this.endpointWebhook}/*`, async (req: express.Request, res: express.Response) => {
+			// Cut away the "/webhook/" to get the registred part of the url
+			const requestUrl = (req as ICustomRequest).parsedUrl!.pathname!.slice(this.endpointWebhook.length + 2);
+
+			let allowedMethods;
+			try {
+				allowedMethods = await this.activeWorkflowRunner.getWebhookMethods(requestUrl);
+				
+				// Add custom "Allow" header to satisfy OPTIONS response.
+				res.append('Allow', allowedMethods);
+			} catch (error) {
+				ResponseHelper.sendErrorResponse(res, error);
+				return;
+			}
+
+			ResponseHelper.sendSuccessResponse(res, {}, true, 204);
+		});
+
 		// GET webhook requests
 		this.app.get(`/${this.endpointWebhook}/*`, async (req: express.Request, res: express.Response) => {
 			// Cut away the "/webhook/" to get the registred part of the url
@@ -1630,6 +1649,25 @@ class App {
 			ResponseHelper.sendSuccessResponse(res, response.data, true, response.responseCode);
 		});
 
+		// HEAD webhook requests (test for UI)
+		this.app.options(`/${this.endpointWebhookTest}/*`, async (req: express.Request, res: express.Response) => {
+			// Cut away the "/webhook-test/" to get the registred part of the url
+			const requestUrl = (req as ICustomRequest).parsedUrl!.pathname!.slice(this.endpointWebhookTest.length + 2);
+
+			let allowedMethods;
+			try {
+				allowedMethods = await this.testWebhooks.getWebhookMethods(requestUrl);
+
+				// Add custom "Allow" header to satisfy OPTIONS response.
+				res.append('Allow', allowedMethods);
+			} catch (error) {
+				ResponseHelper.sendErrorResponse(res, error);
+				return;
+			}
+
+			ResponseHelper.sendSuccessResponse(res, {}, true, 204);
+		});
+
 		// GET webhook requests (test for UI)
 		this.app.get(`/${this.endpointWebhookTest}/*`, async (req: express.Request, res: express.Response) => {
 			// Cut away the "/webhook-test/" to get the registred part of the url

packages/cli/src/TestWebhooks.ts

@@ -110,6 +110,21 @@ export class TestWebhooks {
 		});
 	}
 
+	/**
+	 * Gets all request methods associated with a single test webhook
+	 * @param path webhook path
+	 */
+	async getWebhookMethods(path : string) : Promise<string[]> {
+		const webhookMethods: string[] = this.activeWebhooks!.getWebhookMethods(path);
+
+		if (webhookMethods === undefined) {
+			// The requested webhook is not registered
+			throw new ResponseHelper.ResponseError(`The requested webhook "${path}" is not registered.`, 404, 404);
+		}
+
+		return webhookMethods;
+	}
+
 
 	/**
 	 * Checks if it has to wait for webhook data to execute the workflow. If yes it waits

packages/core/src/ActiveWebhooks.ts

@@ -85,6 +85,21 @@ export class ActiveWebhooks {
 		return this.webhookUrls[webhookKey];
 	}
 
+	/**
+	 * Gets all request methods associated with a single webhook
+	 * @param path 
+	 */
+	getWebhookMethods(path: string): string[] {
+		let methods : string[] = [];
+
+		Object.keys(this.webhookUrls)
+		.filter(key => key.includes(path))
+		.map(key => {
+			methods.push(key.split('|')[0]);
+		});
+
+		return methods;
+	}
 
 	/**
 	 * Returns the ids of all the workflows which have active webhooks

packages/workflow/src/Interfaces.ts

@@ -590,7 +590,7 @@ export interface IWorkflowMetadata {
 	active: boolean;
 }
 
-export type WebhookHttpMethod = 'GET' | 'POST' | 'HEAD';
+export type WebhookHttpMethod = 'GET' | 'POST' | 'HEAD' | 'OPTIONS';
 
 export interface IWebhookResponseData {
 	workflowData?: INodeExecutionData[][];