✨ Add basic Mattermost-Node

packages/nodes-base/nodes/Mattermost/GenericFunctions.ts

@@ -0,0 +1,59 @@
+import {
+	IExecuteFunctions,
+	IHookFunctions,
+	ILoadOptionsFunctions,
+} from 'n8n-core';
+
+import { OptionsWithUri } from 'request';
+import { IDataObject } from 'n8n-workflow';
+
+
+/**
+ * Make an API request to Telegram
+ *
+ * @param {IHookFunctions} this
+ * @param {string} method
+ * @param {string} url
+ * @param {object} body
+ * @returns {Promise<any>}
+ */
+export async function apiRequest(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions, method: string, endpoint: string, body: object, query?: IDataObject): Promise<any> { // tslint:disable-line:no-any
+	const credentials = this.getCredentials('mattermostApi');
+
+	if (credentials === undefined) {
+		throw new Error('No credentials got returned!');
+	}
+
+	query = query || {};
+
+	const options: OptionsWithUri = {
+		method,
+		body,
+		qs: query,
+		uri: `${credentials.baseUrl}/api/v4/${endpoint}`,
+		headers: {
+			Authorization: `Bearer ${credentials.accessToken}`,
+			'content-type': 'application/json; charset=utf-8'
+		},
+		json: true
+	};
+
+	try {
+		return await this.helpers.request!(options);
+	} catch (error) {
+
+		if (error.statusCode === 401) {
+			// Return a clear error
+			throw new Error('The Mattermost credentials are not valid!');
+		}
+
+		if (error.response && error.response.body && error.response.body.message) {
+			// Try to return the error prettier
+			const errorBody = error.response.body;
+			throw new Error(`Mattermost error response: ${errorBody.message}`);
+		}
+
+		// Expected error data did not get returned so throw the actual error
+		throw error;
+	}
+}