fix: modernize docker publishing

ts/rendertron.classes.prerendermanager.ts

@@ -3,9 +3,9 @@ import { PrerenderResult } from './rendertron.classes.prerenderresult.js';
 import * as plugins from './rendertron.plugins.js';
 
 export class PrerenderManager {
-  public smartssrInstance: plugins.smartssr.SmartSSR;
-  public smartrobotsInstance: plugins.smartrobots.Smartrobots;
-  public smartsitemapInstance: plugins.smartsitemap.SmartSitemap;
+  public smartssrInstance!: plugins.smartssr.SmartSSR;
+  public smartrobotsInstance!: plugins.smartrobots.Smartrobots;
+  public smartsitemapInstance!: plugins.smartsitemap.SmartSitemap;
 
   constructor() {}
 
@@ -31,6 +31,9 @@ export class PrerenderManager {
         return null;
       }
     );
+    if (!prerenderResult) {
+      return done.promise;
+    }
     done.resolve(prerenderResult.renderResultString);
     return done.promise;
   }
@@ -64,19 +67,19 @@ export class PrerenderManager {
 
   public async prerenderSitemap(sitemapUrlArg: string) {
     logger.log('info', `prerendering sitemap: ${sitemapUrlArg}`);
-    const parsedSitemap = await this.smartsitemapInstance.parseSitemapUrl(sitemapUrlArg);
-    if (!parsedSitemap.urlset?.url) {
+    const parsedSitemap = await plugins.smartsitemap.SmartSitemap.parseUrl(sitemapUrlArg);
+    if (parsedSitemap.type === 'sitemapindex') {
+      for (const sitemap of parsedSitemap.sitemaps) {
+        await this.prerenderSitemap(sitemap.loc);
+      }
       return;
     }
-    if (!(parsedSitemap.urlset.url instanceof Array)) {
-      await this.getPrerenderResultForUrl(parsedSitemap.urlset.url.loc);
-    } else {
-      for (const url of parsedSitemap.urlset.url) {
-        if (!url?.loc) {
-          continue;
-        }
-        await this.getPrerenderResultForUrl(url.loc);
+
+    for (const url of parsedSitemap.urls) {
+      if (!url?.loc) {
+        continue;
       }
+      await this.getPrerenderResultForUrl(url.loc);
     }
   }