Sitemap: support SSR routes (#6534)

* feat(sitemap): support SSR generated routes

* feat(sitemap): add changeset for SSR support

* refactor: move logic to `astro:build:done`

* generate route to obey `trailingSlash` setting

* add logic to respect "directory" build format

* integration(sitemap): add unit test for ssr support

7 files changed, 96 insertions, 18 deletions

diff --git a/packages/integrations/sitemap/package.json b/packages/integrations/sitemap/package.json
index afd959a62..7c465494e 100644
--- a/packages/integrations/sitemap/package.json
+++ b/packages/integrations/sitemap/package.json
@@ -37,6 +37,7 @@
     "zod": "^3.17.3"
   },
   "devDependencies": {
+    "@astrojs/node": "workspace:*",
     "astro": "workspace:*",
     "astro-scripts": "workspace:*",
     "chai": "^4.3.6",
diff --git a/packages/integrations/sitemap/src/index.ts b/packages/integrations/sitemap/src/index.ts
index e6e45ddd1..0814ae0e1 100644
--- a/packages/integrations/sitemap/src/index.ts
+++ b/packages/integrations/sitemap/src/index.ts
@@ -51,6 +51,8 @@ const OUTFILE = 'sitemap-index.xml';
 
 const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 	let config: AstroConfig;
+	const logger = new Logger(PKG_NAME);
+
 	return {
 		name: PKG_NAME,
 
@@ -59,10 +61,15 @@ const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 				config = cfg;
 			},
 
-			'astro:build:done': async ({ dir, pages }) => {
-				const logger = new Logger(PKG_NAME);
-
+			'astro:build:done': async ({ dir, routes }) => {
 				try {
+					if (!config.site) {
+						logger.warn(
+							'The Sitemap integration requires the `site` astro.config option. Skipping.'
+						);
+						return;
+					}
+
 					const opts = validateOptions(config.site, options);
 
 					const { filter, customPages, serialize, entryLimit } = opts;
@@ -78,12 +85,30 @@ const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 						return;
 					}
 
-					let pageUrls = pages.map((p) => {
-						if (p.pathname !== '' && !finalSiteUrl.pathname.endsWith('/'))
-							finalSiteUrl.pathname += '/';
-						const path = finalSiteUrl.pathname + p.pathname;
-						return new URL(path, finalSiteUrl).href;
-					});
+					let pageUrls = routes.reduce<string[]>((urls, r) => {
+						/**
+						 * Dynamic URLs have entries with `undefined` pathnames
+						 */
+						if (r.pathname) {
+							/**
+							 * remove the initial slash from relative pathname
+							 * because `finalSiteUrl` always has trailing slash
+							 */
+							const path = finalSiteUrl.pathname + r.generate(r.pathname).substring(1);
+
+							let newUrl = new URL(path, finalSiteUrl).href;
+
+							if (config.trailingSlash === 'never') {
+								urls.push(newUrl);
+							} else if (config.build.format === 'directory' && !newUrl.endsWith('/')) {
+								urls.push(newUrl + '/');
+							} else {
+								urls.push(newUrl);
+							}
+						}
+
+						return urls;
+					}, []);
 
 					try {
 						if (filter) {
@@ -95,18 +120,11 @@ const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 					}
 
 					if (customPages) {
-						pageUrls = [...pageUrls, ...customPages];
+						pageUrls = Array.from(new Set([...pageUrls, ...customPages]));
 					}
 
 					if (pageUrls.length === 0) {
-						// offer suggestion for SSR users
-						if (config.output !== 'static') {
-							logger.warn(
-								`No pages found! We can only detect sitemap routes for "static" builds. Since you are using an SSR adapter, we recommend manually listing your sitemap routes using the "customPages" integration option.\n\nExample: \`sitemap({ customPages: ['https://example.com/route'] })\``
-							);
-						} else {
-							logger.warn(`No pages found!\n\`${OUTFILE}\` not created.`);
-						}
+						logger.warn(`No pages found!\n\`${OUTFILE}\` not created.`);
 						return;
 					}
 
diff --git a/packages/integrations/sitemap/test/fixtures/ssr/astro.config.mjs b/packages/integrations/sitemap/test/fixtures/ssr/astro.config.mjs
new file mode 100644
index 000000000..d914d4357
--- /dev/null
+++ b/packages/integrations/sitemap/test/fixtures/ssr/astro.config.mjs
@@ -0,0 +1,12 @@
+import { defineConfig } from 'astro/config';
+import sitemap from '@astrojs/sitemap';
+import nodeServer from '@astrojs/node'
+
+export default defineConfig({
+  integrations: [sitemap()],
+	site: 'http://example.com',
+	output: 'server',
+	adapter: nodeServer({
+		mode: "standalone"
+	})
+})
diff --git a/packages/integrations/sitemap/test/fixtures/ssr/package.json b/packages/integrations/sitemap/test/fixtures/ssr/package.json
new file mode 100644
index 000000000..980e02e73
--- /dev/null
+++ b/packages/integrations/sitemap/test/fixtures/ssr/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@test/sitemap-trailing-slash",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*",
+    "@astrojs/sitemap": "workspace:*"
+  }
+}
diff --git a/packages/integrations/sitemap/test/fixtures/ssr/src/pages/one.astro b/packages/integrations/sitemap/test/fixtures/ssr/src/pages/one.astro
new file mode 100644
index 000000000..0c7fb90a7
--- /dev/null
+++ b/packages/integrations/sitemap/test/fixtures/ssr/src/pages/one.astro
@@ -0,0 +1,8 @@
+<html>
+	<head>
+		<title>One</title>
+	</head>
+	<body>
+		<h1>One</h1>
+	</body>
+</html>
diff --git a/packages/integrations/sitemap/test/fixtures/ssr/src/pages/two.astro b/packages/integrations/sitemap/test/fixtures/ssr/src/pages/two.astro
new file mode 100644
index 000000000..e7ba9910e
--- /dev/null
+++ b/packages/integrations/sitemap/test/fixtures/ssr/src/pages/two.astro
@@ -0,0 +1,8 @@
+<html>
+	<head>
+		<title>Two</title>
+	</head>
+	<body>
+		<h1>Two</h1>
+	</body>
+</html>
diff --git a/packages/integrations/sitemap/test/ssr.test.js b/packages/integrations/sitemap/test/ssr.test.js
new file mode 100644
index 000000000..e6f8412d5
--- /dev/null
+++ b/packages/integrations/sitemap/test/ssr.test.js
@@ -0,0 +1,22 @@
+import { loadFixture, readXML } from './test-utils.js';
+import { expect } from 'chai';
+
+describe('SSR support', () => {
+	/** @type {import('./test-utils.js').Fixture} */
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			root: './fixtures/ssr/',
+		});
+		await fixture.build();
+	});
+
+	it('SSR pages require zero config', async () => {
+		const data = await readXML(fixture.readFile('/client/sitemap-0.xml'));
+		const urls = data.urlset.url;
+
+		expect(urls[0].loc[0]).to.equal('http://example.com/one/');
+		expect(urls[1].loc[0]).to.equal('http://example.com/two/');
+	});
+});