feat(@astro/sitemap): custom sitemaps

.changeset/red-candles-invite.md

@@ -0,0 +1,27 @@
+---
+'@astrojs/sitemap': minor
+---
+
+Adds a `customSitemaps` option to include extra sitemaps in the `sitemap-index.xml` file generated by Astro.
+
+This is useful for multi-framework setups on the same domain as your Astro site (`example.com`), such as a blog at `example.com/blog` whose sitemap is generated by another framework.
+
+The following example shows configuring your Astro site to include sitemaps for an externally-generated blog and help center along with the generated sitemap entries in `sitemap-index.xml`:
+
+Example:
+
+```js
+import { defineConfig } from 'astro/config';
+import sitemap from '@astrojs/sitemap';
+
+export default defineConfig({
+  site: 'https://example.com',
+  integrations: [
+    sitemap({
+      customSitemaps: ['https://example.com/blog/sitemap.xml', 'https://example.com/helpcenter/sitemap.xml'],
+    }),
+  ],
+});
+```
+
+Learn more in the [`@astrojs/sitemap` configuration documentation](https://docs.astro.build/en/guides/integrations-guide/sitemap/#configuration).

packages/integrations/sitemap/src/index.ts

@@ -20,6 +20,7 @@ export type SitemapOptions =
 	| {
 			filenameBase?: string;
 			filter?(page: string): boolean;
+			customSitemaps?: string[];
 			customPages?: string[];
 
 			i18n?: {
@@ -88,7 +89,7 @@ const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 
 					const opts = validateOptions(config.site, options);
 
-					const { filenameBase, filter, customPages, serialize, entryLimit } = opts;
+					const { filenameBase, filter, customPages, customSitemaps, serialize, entryLimit } = opts;
 
 					const outFile = `${filenameBase}-index.xml`;
 					const finalSiteUrl = new URL(config.base, config.site);
@@ -175,6 +176,7 @@ const createPlugin = (options?: SitemapOptions): AstroIntegration => {
 							publicBasePath: config.base,
 							sourceData: urlData,
 							limit: entryLimit,
+              customSitemaps,
 							xslURL: xslURL,
 						},
 						config,

packages/integrations/sitemap/src/schema.ts

@@ -8,6 +8,7 @@ export const SitemapOptionsSchema = z
 	.object({
 		filenameBase: z.string().optional().default(SITEMAP_CONFIG_DEFAULTS.filenameBase),
 		filter: z.function().args(z.string()).returns(z.boolean()).optional(),
+		customSitemaps: z.string().url().array().optional(),
 		customPages: z.string().url().array().optional(),
 		canonicalURL: z.string().url().optional(),
 		xslURL: z.string().optional(),

packages/integrations/sitemap/src/write-sitemap.ts

@@ -4,15 +4,15 @@ import { normalize, resolve } from 'node:path';
 import { pipeline, Readable } from 'node:stream';
 import { promisify } from 'node:util';
 import type { AstroConfig } from 'astro';
-
-import { SitemapAndIndexStream, SitemapStream } from 'sitemap';
+import { SitemapAndIndexStream, SitemapIndexStream, SitemapStream } from 'sitemap';
 import replace from 'stream-replace-string';
 import type { SitemapItem } from './index.js';
 
 type WriteSitemapConfig = {
 	filenameBase: string;
 	hostname: string;
 	sitemapHostname?: string;
+	customSitemaps?: string[];
 	sourceData: SitemapItem[];
 	destinationDir: string;
 	publicBasePath?: string;
@@ -29,6 +29,7 @@ export async function writeSitemap(
 		sourceData,
 		destinationDir,
 		limit = 50000,
+		customSitemaps = [],
 		publicBasePath = './',
 		xslURL: xslUrl,
 	}: WriteSitemapConfig,
@@ -70,5 +71,13 @@ export async function writeSitemap(
 
 	const src = Readable.from(sourceData);
 	const indexPath = resolve(destinationDir, `./${filenameBase}-index.xml`);
+	for (const customSitemap of customSitemaps) {
+		SitemapIndexStream.prototype._transform.call(
+			sitemapAndIndexStream,
+			{ url: customSitemap },
+			'utf8',
+			() => {},
+		);
+	}
 	return promisify(pipeline)(src, sitemapAndIndexStream, createWriteStream(indexPath));
 }

packages/integrations/sitemap/test/custom-pages.test.js

@@ -0,0 +1,29 @@
+import assert from 'node:assert/strict';
+import { before, describe, it } from 'node:test';
+import { sitemap } from './fixtures/static/deps.mjs';
+import { loadFixture, readXML } from './test-utils.js';
+
+describe('Sitemap with custom pages', () => {
+  /** @type {import('./test-utils.js').Fixture} */
+  let fixture;
+  /** @type {string[]} */
+  let urls;
+
+  before(async () => {
+    fixture = await loadFixture({
+      root: './fixtures/static/',
+      integrations: [
+        sitemap({
+          customPages: ['http://example.com/custom-page'],
+        }),
+      ],
+    });
+    await fixture.build();
+    const data = await readXML(fixture.readFile('/sitemap-0.xml'));
+    urls = data.urlset.url.map((url) => url.loc[0]);
+  });
+
+  it('includes defined custom pages', async () => {
+    assert.equal(urls.includes('http://example.com/custom-page'), true);
+  });
+});

packages/integrations/sitemap/test/custom-sitemaps.test.js

@@ -0,0 +1,29 @@
+import assert from 'node:assert/strict';
+import { before, describe, it } from 'node:test';
+import { sitemap } from './fixtures/static/deps.mjs';
+import { loadFixture, readXML } from './test-utils.js';
+
+describe('Custom sitemaps', () => {
+  /** @type {import('./test-utils.js').Fixture} */
+  let fixture;
+  /** @type {string[]} */
+  let urls;
+
+  before(async () => {
+    fixture = await loadFixture({
+      root: './fixtures/static/',
+      integrations: [
+        sitemap({
+          customSitemaps: ['http://example.com/custom-sitemap.xml'],
+        }),
+      ],
+    });
+    await fixture.build();
+    const data = await readXML(fixture.readFile('/sitemap-index.xml'));
+    urls = data.sitemapindex.sitemap.map((s) => s.loc[0]);
+  });
+
+  it('includes defined custom sitemaps', async () => {
+    assert.equal(urls.includes('http://example.com/custom-sitemap.xml'), true);
+  });
+});