(sitemap) Root site URL in generated sitemap does not respect AstroConfig.trailingSlash

[gislerro]

Astro Info

Astro                    v4.5.18
Node                     v18.18.0
System                   Linux (x64)
Package Manager          unknown
Output                   static
Adapter                  none
Integrations             @astrojs/sitemap

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

Using this Astro Config:

import { defineConfig } from 'astro/config';
import sitemap from '@astrojs/sitemap';

export default defineConfig({
	site: 'https://example.com',
	trailingSlash: 'never',
	integrations: [sitemap()],
});

results in the following sitemap-0.xml being generated after astro build on a basic setup two pages index.astro and about.astro:

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
   xmlns:news="http://www.google.com/schemas/sitemap-news/0.9"
   xmlns:xhtml="http://www.w3.org/1999/xhtml"
   xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"
   xmlns:video="http://www.google.com/schemas/sitemap-video/1.1">
   <url>
      <loc>https://example.com/</loc>
   </url>
   <url>
      <loc>https://example.com/about</loc>
   </url>
</urlset>

What's the expected result?

All urls in the generated sitemap conform to the trailingSlash config option:

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
   xmlns:news="http://www.google.com/schemas/sitemap-news/0.9"
   xmlns:xhtml="http://www.w3.org/1999/xhtml"
   xmlns:image="http://www.google.com/schemas/sitemap-image/1.1"
   xmlns:video="http://www.google.com/schemas/sitemap-video/1.1">
   <url>
      <loc>https://example.com</loc>
   </url>
   <url>
      <loc>https://example.com/about</loc>
   </url>
</urlset>

Link to Minimal Reproducible Example

https://stackblitz.com/edit/withastro-astro-6n4cpf?file=dist%2Fsitemap-0.xml

Participation

• I am willing to submit a pull request for this issue.

[gislerro]

After some investigating this seems to be an upstream issue in sitemap.js. I could implement the workaround suggested if it's desired

[ematipico]

I believe we could attempt to apply the workaround. @gislerro, would you like to send a PR?

[tholyong]

Hi, is there a way to maintain a trailing slash for the root URL even when AstroConfig.trailingSlash is 'never'? The majority of the browsers will land/redirect the root URL with a trailing slash (although we can't see it, but when we copy the URL the trailing slash is included). So in the Sitemap and for a better SEO practice, it is probably a good idea to have the root URL with the trailing slash included even when AstroConfig.trailingSlash is 'never'.