fix(Ghost Node): Fix post tags and add credential tests (#3278)

* Renamed Tag IDs to Tags and changed the value to tag.name

* Updated credentials to use new system

* Nodelinter changes

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

@@ -10,38 +10,30 @@ import {
 } from 'n8n-core';
 
 import {
-	IDataObject, NodeApiError,
+	IDataObject,
+	JsonObject,
+	NodeApiError,
 } from 'n8n-workflow';
 
-import jwt from 'jsonwebtoken';
-
 export async function ghostApiRequest(this: IHookFunctions | IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions, method: string, endpoint: string, body: any = {}, query: IDataObject = {}, uri?: string): Promise<any> { // tslint:disable-line:no-any
 
 	const source = this.getNodeParameter('source', 0) as string;
 
 	let credentials;
 	let version;
-	let token;
+	let credentialType;
 
 	if (source === 'contentApi') {
 		//https://ghost.org/faq/api-versioning/
 		version = 'v3';
-		credentials = await this.getCredentials('ghostContentApi');
-		query.key = credentials.apiKey as string;
+		credentialType = 'ghostContentApi';
 	} else {
 		version = 'v2';
-		credentials = await this.getCredentials('ghostAdminApi');
-		// Create the token (including decoding secret)
-		const [id, secret] = (credentials.apiKey as string).split(':');
-
-		token = jwt.sign({}, Buffer.from(secret, 'hex'), {
-			keyid: id,
-			algorithm: 'HS256',
-			expiresIn: '5m',
-			audience: `/${version}/admin/`,
-		});
+		credentialType = 'ghostAdminApi';
 	}
 
+	credentials = await this.getCredentials(credentialType);
+
 	const options: OptionsWithUri = {
 		method,
 		qs: query,
@@ -50,17 +42,10 @@ export async function ghostApiRequest(this: IHookFunctions | IExecuteFunctions |
 		json: true,
 	};
 
-	if (token) {
-		options.headers = {
-			Authorization: `Ghost ${token}`,
-		};
-	}
-
 	try {
-		return await this.helpers.request!(options);
-
-	} catch (error) {
-		throw new NodeApiError(this.getNode(), error);
+		return await this.helpers.requestWithAuthentication.call(this, credentialType, options);
+	} catch(error) {
+		throw new NodeApiError(this.getNode(), error as JsonObject);
 	}
 }