fix for list types in Fn::Join

Author: ljacobsson

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mhlabs/cfn-diagram",
-  "version": "1.1.8",
+  "version": "1.1.9",
   "description": "CLI tool to visualise CloudFormation templates as draw.io or HTML diagrams",
   "main": "index.js",
   "scripts": {

resources/JsonUtil.js

@@ -1,8 +1,9 @@
 function createPseudoResources(template, current) {
-  current = current || template;
+  current = current || template.Resources;
   for (var k in current) {
     if (current[k]["Fn::Join"]) {
-      current[k] = current[k]["Fn::Join"][1].join(current[k]["Fn::Join"][0]);
+      const joinList = current[k]["Fn::Join"][1]    
+      current[k] = (Array.isArray(joinList) ? joinList : [joinList]).join(current[k]["Fn::Join"][0]);
     }
     if (typeof current[k] === "object" && current[k] !== null) {
       createPseudoResources(template, current[k]);