Adding FriendGrid example node (updated version of the one in the n8n docs)

nodes/FriendGrid/GenericFunctions.ts

@@ -0,0 +1,53 @@
+import {
+	OptionsWithUri,
+} from 'request';
+
+import {
+	IExecuteFunctions,
+	IExecuteSingleFunctions,
+	IHookFunctions,
+	ILoadOptionsFunctions,
+} from 'n8n-core';
+
+import {
+	IDataObject,
+	NodeApiError,
+	NodeOperationError,
+} from 'n8n-workflow';
+
+export async function friendGridApiRequest(this: IHookFunctions | IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions,
+	method: string, endpoint: string, body?: object, query?: object, uri?: string): Promise<any> { // tslint:disable-line:no-any
+
+	//Get credentials the user provided for this node
+	const credentials = await this.getCredentials('friendGridApi') as IDataObject;
+
+	if (credentials === undefined) {
+		throw new NodeOperationError(this.getNode(), 'No credentials got returned!');
+	}
+
+	//Make http request according to <https://sendgrid.com/docs/api-reference/>
+	const options: OptionsWithUri = {
+		method,
+		headers: {
+			'Accept': ' application/json',
+			'Authorization': `Bearer ${credentials.apiKey}`,
+		},
+		qs: query,
+		body,
+		uri: uri || `https://api.sendgrid.com/v3/marketing/${endpoint}`,
+		json: true,
+	};
+
+	if (Object.keys(options.qs).length === 0) {
+		delete options.qs;
+	}
+	if (Object.keys(options.body).length === 0) {
+		delete options.body;
+	}
+
+	try {
+		return this.helpers.request!(options);
+	} catch (error) {
+		throw new NodeApiError(this.getNode(), error);
+	}
+}