Resolves issue #154: Enables field parsing even when some items may not include field (#155)

Author: rchiba

Diff for: src/assets/sitemapper.js

@@ -331,7 +331,7 @@ export default class Sitemapper {
               } else {
                   let fields = {};
                   for (const [field, active] of Object.entries(this.fields)) {
-                    if(active){
+                    if(active && site[field]){
                       fields[field] = site[field][0]
                     }
                   }

Diff for: src/tests/test.ts.ts

@@ -119,9 +119,9 @@ describe('Sitemapper', function () {
         });
     });
 
-    it('https://www.channable.com/sitemap.xml sitemaps should contain extra fields', function (done) {
+    it('https://wp.seantburke.com/sitemap.xml sitemaps should contain extra fields', function (done) {
       this.timeout(30000);
-      const url = 'https://www.channable.com/sitemap.xml';
+      const url = 'https://wp.seantburke.com/sitemap.xml';
       sitemapper = new Sitemapper({
         fields: { "loc": true,
           "lastmod": true,