chore: fix sitemap (#16026)

* chore: fix sitemap

* refactor conditions for generating sitemaps

docs/.eleventy.js

@@ -407,6 +407,26 @@ module.exports = function(eleventyConfig) {
         }
     });
 
+    /*
+     * Generate the sitemap only in certain contexts to prevent unwanted discovery of sitemaps that
+     * contain URLs we'd prefer not to appear in search results (URLs in sitemaps are considered important).
+     * In particular, we don't want to deploy https://eslint.org/docs/head/sitemap.xml
+     * We want to generate the sitemap for:
+     *   - Local previews
+     *   - Netlify deploy previews
+     *   - Netlify production deploy of the `latest` branch (https://eslint.org/docs/latest/sitemap.xml)
+     *
+     * Netlify always sets `CONTEXT` environment variable. If it isn't set, we assume this is a local build.
+     */
+    if (
+        process.env.CONTEXT && // if this is a build on Netlify ...
+        process.env.CONTEXT !== "deploy-preview" && // ... and not for a deploy preview ...
+        process.env.BRANCH !== "latest" // .. and not of the `latest` branch ...
+    ) {
+        eleventyConfig.ignores.add("src/static/sitemap.njk"); // ... then don't generate the sitemap.
+    }
+
+
     return {
         passthroughFileCopy: true,
 

docs/src/static/robots.njk

@@ -3,6 +3,5 @@ layout: false
 permalink: robots.txt
 eleventyExcludeFromCollections: true
 ---
-Sitemap: {{ metadata.url }}/sitemap.xml
 User-agent: *
 Disallow: /

docs/src/static/sitemap.njk

@@ -6,9 +6,9 @@ eleventyExcludeFromCollections: true
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
     {% for page in collections.all %}
         <url>
-            <loc>{{ site.url }}{{ page.url | url | prettyURL }}</loc>
+            <loc>{{ ["https://", site.hostname, page.url | url | prettyURL] | join }}</loc>
             <lastmod>{{ page.date.toISOString() }}</lastmod>
-            <changefreq>{{ page.data.changeFreq or &quot;monthly&quot; }}</changefreq>
+            <changefreq>{{ page.data.changeFreq if page.data.changeFreq else "weekly" }}</changefreq>
         </url>
     {% endfor %}
 </urlset>