Generating a sitemap for [...slug].astro pages with slugs starting with / results in broken URLs

[moose96]

Astro Info

Astro                    v4.3.1
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

I am creating my own integration with CMS and I've decided to store all slugs inside content management system. Thus, my pages folder contains only one page - [...slug].astro. I have complicated logic in getStaticPaths but it migth be simplified to this:

export async function getStaticPaths() {
  return [
    {
      params: {
        slug: undefined,
      }
    },
    {
      params: {
        slug: '/blog'
      }
    },
    {
      params: {
        slug: '/test'
      }
    }
  ];
}

Let's assume my astro.config.mjs looks like:

export default defineConfig({
  site: 'https://example.com',
  integrations: [sitemap()],
});

In this case I get sitemap:

<?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://blog/</loc> <!-- <- wrong url here -->
    </url>
    <url>
        <loc>https://example.com/</loc>
    </url>
    <url>
        <loc>https://test/</loc><!-- <- wrong url here -->
    </url>
</urlset>

What's the expected result?

I expect sitemap to be:

<?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/blog/</loc>
    </url>
    <url>
        <loc>https://example.com/</loc>
    </url>
    <url>
        <loc>https://example.com/test/</loc>
    </url>
</urlset>

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-e5zwsf?file=dist%2Fsitemap-0.xml

Participation

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

[bluwy]

I'm not sure if slugs should have a leading slash or trailing slash, I feel like there would be more bugs down the line if you do so, and not just an issue with the sitemap integration 🤔

[moose96]

I'm not sure if slugs should have a leading slash or trailing slash, I feel like there would be more bugs down the line if you do so, and not just an issue with the sitemap integration 🤔

What kind of bugs? We use leading slashes in our application and everything works except generating sitemap. That's why I think it's the issue with the sitemap integration. If using leading or trailing slashes was forbidded there should be any validation while generating static paths or there should be a note in a documentation that you can't use this kind of slashes in the code with explanation.

[florian-lefebvre]

I agree with @bluwy, I didn't think leading slashes would be allowed as parameters. Not sure what's the best way here, maybe we should do the following:

1. If a param starts or ends with a /, remove it
2. Log a warning
3. In Astro 5, update the regex and fail is specified?

[ematipico]

@florian-lefebvre, where should this warning be printed?

[florian-lefebvre]

I'm not 100% sure when this runs in Astro, but basically as soon as we get the result of the getStaticPaths function that returns an "invalid" param?

[ematipico]

@matthewp what do you think? Does it make sense to you?

[matthewp]

I think @florian-lefebvre's plan makes sense. There was a related issue where someone was confused today.

[matthewp]

After discussing this we realized that having double slashes is valid in a URL path, (/foo//about is a valid URL!), so we don't want to remove those even though it's what you would want most of the time.

Another idea that could help is having a utility like pathToParam(path) that people can use for this scenario, given that it's a common thing to try and do. With this utility method we can do whatever we want/need to normalize the param.

[ematipico]

Closing. This will be fixed in Astro v5. Follow #7962 (comment) for more information.

Params can contain slashes, but they must be encoded inside getStaticPaths, then the user must decode them when using them