fix: filter sitemap pathnames from generated sitemap.xml

src/core/sitemap.test.ts

@@ -187,6 +187,73 @@ describe('generateSitemap', () => {
     expect(sitemap).toContain('<loc>https://example.com/products/</loc>');
   });
 
+  it('filters /sitemap, /sitemap-N, and /sitemap-index from config.pages', () => {
+    mockFs.readdirSync.mockReturnValue([]);
+    const configWithSitemapPages = {
+      ...baseConfig,
+      pages: [
+        { pathname: '/', title: 'Home', description: '', content: '' },
+        { pathname: '/about', title: 'About', description: '', content: '' },
+        { pathname: '/sitemap', title: '', description: '', content: '' },
+        { pathname: '/sitemap-0', title: '', description: '', content: '' },
+        { pathname: '/sitemap-1', title: '', description: '', content: '' },
+        { pathname: '/sitemap-index', title: '', description: '', content: '' },
+        { pathname: '/sitemap.xml', title: '', description: '', content: '' },
+        { pathname: '/sitemap-0.xml', title: '', description: '', content: '' },
+      ],
+    };
+
+    const sitemap = generateSitemap(configWithSitemapPages);
+
+    expect(sitemap).toContain('<loc>https://example.com/about</loc>');
+    expect(sitemap).not.toContain('/sitemap-0');
+    expect(sitemap).not.toContain('/sitemap-1');
+    expect(sitemap).not.toContain('/sitemap-index');
+    expect(sitemap).not.toContain('/sitemap.xml');
+    expect(sitemap).not.toMatch(/<loc>https:\/\/example\.com\/sitemap<\/loc>/);
+  });
+
+  it('preserves legitimate paths that start with sitemap- but are not sitemap files', () => {
+    mockFs.readdirSync.mockReturnValue([]);
+    const configWithSitemapNamedPages = {
+      ...baseConfig,
+      pages: [
+        { pathname: '/sitemap-guide', title: 'Sitemap Guide', description: '', content: '' },
+        { pathname: '/sitemap-tutorial', title: 'Tutorial', description: '', content: '' },
+        { pathname: '/sitemaps-explained', title: 'Explained', description: '', content: '' },
+        { pathname: '/sitemap-0', title: '', description: '', content: '' },
+      ],
+    };
+
+    const sitemap = generateSitemap(configWithSitemapNamedPages);
+
+    expect(sitemap).toContain('<loc>https://example.com/sitemap-guide</loc>');
+    expect(sitemap).toContain('<loc>https://example.com/sitemap-tutorial</loc>');
+    expect(sitemap).toContain('<loc>https://example.com/sitemaps-explained</loc>');
+    expect(sitemap).not.toContain('<loc>https://example.com/sitemap-0</loc>');
+  });
+
+  it('filters sitemap-named files discovered in contentDir', () => {
+    mockFs.readdirSync.mockReturnValue([
+      'index.md',
+      'about.md',
+      'sitemap-0.html',
+      'sitemap-index.html',
+      'sitemap-guide.md',
+    ]);
+    mockFs.statSync.mockReturnValue({
+      isDirectory: () => false,
+      isFile: () => true,
+    });
+
+    const sitemap = generateSitemap(baseConfig);
+
+    expect(sitemap).toContain('<loc>https://example.com/about</loc>');
+    expect(sitemap).toContain('<loc>https://example.com/sitemap-guide</loc>');
+    expect(sitemap).not.toContain('/sitemap-0');
+    expect(sitemap).not.toContain('/sitemap-index');
+  });
+
   it('should handle subdirectories recursively', () => {
     const files = ['index.md', 'blog', 'docs'];
 

src/core/sitemap.ts

@@ -37,19 +37,42 @@ function escapeXml(str: string): string {
     .replace(/'/g, ''');
 }
 
+function isSitemapPathname(pathname: string): boolean {
+  // Matches sitemap output produced by plugins like @astrojs/sitemap:
+  // /sitemap, /sitemap-0, /sitemap-1, /sitemap-index, /sitemap.xml, /sitemap-0.xml
+  // Does NOT match legitimate user pages like /sitemap-guide or /sitemaps-explained.
+  return /^\/sitemap(-\d+|-index)?(\.xml)?$/i.test(pathname);
+}
+
+function pathnameFromUrl(url: string, baseUrl: string): string {
+  // Always extract the pathname portion so the sitemap-name filter still applies
+  // even when the URL doesn't share the configured base (e.g. a different host
+  // sneaks in via collectUrls). Falls back to the raw input only if URL parsing
+  // fails entirely, which the regex below will then ignore.
+  try {
+    return new URL(url, baseUrl).pathname;
+  } catch {
+    return url;
+  }
+}
+
 export function generateSitemap(config: ResolvedAeoConfig): string {
   const urls: string[] = [];
 
   // Add discovered pages from framework plugin
   if (config.pages && config.pages.length > 0) {
     for (const page of config.pages) {
+      if (isSitemapPathname(page.pathname)) continue;
       urls.push(`${config.url}${page.pathname === '/' ? '' : page.pathname}`);
     }
   }
 
   // Add markdown/html files from content dir
   if (config.contentDir && existsSync(config.contentDir)) {
-    urls.push(...collectUrls(config.contentDir, config));
+    const contentUrls = collectUrls(config.contentDir, config).filter(
+      (url) => !isSitemapPathname(pathnameFromUrl(url, config.url))
+    );
+    urls.push(...contentUrls);
   }
 
   const lines: string[] = [