✨ Add Discourse Node (#1348)

* ✨ Discourse Node

* ⚡ Add missing credential file

* ⚡ Improvements

* ⚡ Improvements

* ⚡ Minor improvements on Discourse Node

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

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

@@ -0,0 +1,64 @@
+import {
+	OptionsWithUri,
+} from 'request';
+
+import {
+	IExecuteFunctions,
+	IExecuteSingleFunctions,
+	ILoadOptionsFunctions,
+} from 'n8n-core';
+
+import {
+	IDataObject,
+} from 'n8n-workflow';
+
+export async function discourseApiRequest(this: IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions, method: string, path: string, body: any = {}, qs: IDataObject = {}, option = {}): Promise<any> { // tslint:disable-line:no-any
+
+	const credentials = this.getCredentials('discourseApi') as IDataObject;
+
+	const options: OptionsWithUri = {
+		headers: {
+			'Api-Key': credentials.apiKey,
+			'Api-Username': credentials.username,
+		},
+		method,
+		body,
+		qs,
+		uri: `${credentials.url}${path}`,
+		json: true,
+	};
+
+	try {
+		if (Object.keys(body).length === 0) {
+			delete options.body;
+		}
+		//@ts-ignore
+		return await this.helpers.request.call(this, options);
+	} catch (error) {
+		if (error.response && error.response.body && error.response.body.errors) {
+
+			const errors = error.response.body.errors;
+			// Try to return the error prettier
+			throw new Error(
+				`Discourse error response [${error.statusCode}]: ${errors.join('|')}`,
+			);
+		}
+		throw error;
+	}
+}
+
+export async function discourseApiRequestAllItems(this: IExecuteFunctions | ILoadOptionsFunctions, method: string, endpoint: string, body: any = {}, query: IDataObject = {}): Promise<any> { // tslint:disable-line:no-any
+
+	const returnData: IDataObject[] = [];
+
+	let responseData;
+	query.page = 1;
+	do {
+		responseData = await discourseApiRequest.call(this, method, endpoint, body, query);
+		returnData.push.apply(returnData, responseData);
+		query.page++;
+	} while (
+		responseData.length !== 0
+	);
+	return returnData;
+}