Add support for SSR (withastro#1255)

Co-authored-by: Patrick Jakubik <37963339+patryk-smc@users.noreply.github.com>
Co-authored-by: Roni Costa <622159+ronildo@users.noreply.github.com>
Co-authored-by: Ryan Russell <523300+ryanrussell@users.noreply.github.com>
Co-authored-by: HiDeoo <494699+HiDeoo@users.noreply.github.com>
Co-authored-by: Murali Manohar Varma <67296473+mmv-dev@users.noreply.github.com>
Co-authored-by: Marcelo Cardoso <33183880+marcelovicentegc@users.noreply.github.com>
Co-authored-by: Aaron Siddhartha Mondal <28633256+aaronmondal@users.noreply.github.com>
Co-authored-by: Chris Swithinbank <357379+delucis@users.noreply.github.com>
Co-authored-by: Sarah Rainsberger <5098874+sarah11918@users.noreply.github.com>

.changeset/ninety-singers-film.md

@@ -0,0 +1,7 @@
+---
+'@astrojs/starlight': patch
+---
+
+Improves performance of computing the last updated times from Git history.
+
+Instead of executing `git` for each docs page, it is now executed twice regardless of the number of pages.

.changeset/quiet-penguins-wonder.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/starlight': patch
+---
+
+Fixes last updated times on projects with custom `srcDir`

.changeset/six-phones-boil.md

@@ -0,0 +1,16 @@
+---
+'@astrojs/starlight': minor
+---
+
+Adds support for server-rendered Starlight pages.
+
+When building a project with `hybrid` or `server` output mode, a new `prerender` option on Starlight config can be set to `false` to make all Starlight pages be rendered on-demand:
+
+```ts
+export default defineConfig({
+  output: 'server',
+  integrations: [starlight({
+    prerender: false
+  })],
+})
+```

docs/src/content/docs/manual-setup.mdx

@@ -125,6 +125,6 @@ In the future, we plan to support this use case better to avoid the need for the
 
 ### Use Starlight with SSR
 
-You can use Starlight alongside custom on-demand rendered pages in your project by following the [“On-demand Rendering Adapters”](https://docs.astro.build/en/guides/server-side-rendering/) guide in Astro’s docs.
+To enable SSR, follow the [“On-demand Rendering Adapters”](https://docs.astro.build/en/guides/server-side-rendering/) guide in Astro’s docs to add a server adapter to your Starlight project.
 
-Currently, documentation pages generated by Starlight are always prerendered regardless of your project's output mode. We hope to be able to support on-demand rendering for Starlight pages soon.
+Documentation pages generated by Starlight are pre-rendered by default regardless of your project's output mode. To opt out of pre-rendering your Starlight pages, set the [`prerender` config option](/reference/configuration/#prerender) to `false`.

docs/src/content/docs/reference/configuration.mdx

@@ -455,6 +455,18 @@ Define whether Starlight’s default site search provider [Pagefind](https://pag
 Set to `false` to disable indexing your site with Pagefind.
 This will also hide the default search UI if in use.
 
+Pagefind cannot be enabled when the [`prerender`](#prerender) option is set to `false`.
+
+### `prerender`
+
+**type:** `boolean`  
+**default:** `true`
+
+Define whether Starlight pages should be pre-rendered to static HTML or on-demand rendered by an [SSR adapter](https://docs.astro.build/en/guides/server-side-rendering/).
+
+Starlight pages are pre-rendered by default.
+If you are using an SSR adapter and want to render Starlight pages on demand, set `prerender: false`.
+
 ### `head`
 
 **type:** [`HeadConfig[]`](#headconfig)

packages/starlight/.gitignore

@@ -1,4 +1,4 @@
 # Astro generates this during tests, but we want to ignore it.
-src/env.d.ts
-__tests__/**/env.d.ts
+env.d.ts
 __tests__/**/types.d.ts
+.astro

packages/starlight/__e2e__/collection-config.test.ts

@@ -2,12 +2,13 @@ import { expect, testFactory } from './test-utils';
 
 // This fixture contains a space in the directory so that we have a smoke test for building
 // Starlight projects with pathnames like this, which are a common source of bugs.
-const test = await testFactory('./fixtures/custom src-dir/');
+const test = testFactory('./fixtures/custom src-dir/');
 
 test('builds a custom page using the `<StarlightPage>` component and a custom `srcDir`', async ({
 	page,
-	starlight,
+	getProdServer,
 }) => {
+	const starlight = await getProdServer();
 	await starlight.goto('/custom');
 
 	await expect(page.getByText('Hello')).toBeVisible();

packages/starlight/__e2e__/fixtures/git/.gitignore

@@ -0,0 +1,10 @@
+# This fixture is used for the E2E tests related to Git where
+# a new repo is created. Nested repos do not inherit the .gitignore
+# options from the parent repo, so even though these files are
+# already ignored on the package they have to be re-declared here.
+# Do not delete this file or the Git tests will try to index and
+# and commit all the node_modules and generated files from the test.
+env.d.ts
+.astro
+/node_modules/
+/dist/

packages/starlight/__e2e__/fixtures/git/astro.config.mjs

@@ -0,0 +1,11 @@
+import starlight from '@astrojs/starlight';
+import { defineConfig } from 'astro/config';
+
+export default defineConfig({
+	integrations: [
+		starlight({
+			title: 'Git',
+			pagefind: false,
+		}),
+	],
+});

packages/starlight/__e2e__/fixtures/git/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "@e2e/git",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/starlight": "workspace:*",
+    "astro": "^4.15.3"
+  }
+}

packages/starlight/__e2e__/fixtures/git/src/content/config.ts

@@ -0,0 +1,6 @@
+import { defineCollection } from 'astro:content';
+import { docsSchema } from '@astrojs/starlight/schema';
+
+export const collections = {
+	docs: defineCollection({ schema: docsSchema() }),
+};

packages/starlight/__e2e__/fixtures/git/src/content/docs/index.md

@@ -0,0 +1,6 @@
+---
+title: Home Page
+lastUpdated: true
+---
+
+Home page content

packages/starlight/__e2e__/fixtures/ssr/astro.config.mjs

@@ -0,0 +1,25 @@
+import { defineConfig } from 'astro/config';
+import starlight from '@astrojs/starlight';
+import node from '@astrojs/node';
+
+const prerendering = process.env.STARLIGHT_PRERENDER === 'yes';
+
+export default defineConfig({
+	output: 'server',
+	adapter: node({ mode: 'standalone' }),
+	compressHTML: false, // for easier debugging
+	// Output to different folders and expose on different ports
+	// on each case so the servers don't conflict with
+	// each other during tests.
+	outDir: prerendering ? 'dist' : 'build',
+	server: {
+		port: prerendering ? 4322 : 4321,
+	},
+	integrations: [
+		starlight({
+			title: 'SSR',
+			prerender: prerendering,
+			pagefind: false,
+		}),
+	],
+});

packages/starlight/__e2e__/fixtures/ssr/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "@e2e/ssr",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "@astrojs/node": "^8.3.2",
+    "@astrojs/starlight": "workspace:*",
+    "astro": "^4.15.3"
+  }
+}

packages/starlight/__e2e__/fixtures/ssr/src/component/ServerCheck.astro

@@ -0,0 +1,15 @@
+---
+function checkServer() {
+	try {
+		Astro.clientAddress;
+
+		return true;
+	} catch {
+		// Accessing `clientAddress` during build time
+		// fails, so it is not SSR.
+		return false;
+	}
+}
+---
+
+<div id="server-check">{checkServer() ? 'On server' : 'Not server'}</div>

packages/starlight/__e2e__/fixtures/ssr/src/content/config.ts

@@ -0,0 +1,6 @@
+import { defineCollection } from 'astro:content';
+import { docsSchema } from '@astrojs/starlight/schema';
+
+export const collections = {
+	docs: defineCollection({ schema: docsSchema() }),
+};

packages/starlight/__e2e__/fixtures/ssr/src/content/docs/404.mdx

@@ -0,0 +1,9 @@
+---
+title: Not Found
+template: splash
+lastUpdate: true
+---
+
+import ServerCheck from '../../component/ServerCheck.astro';
+
+<ServerCheck />

packages/starlight/__e2e__/fixtures/ssr/src/content/docs/content.mdx

@@ -0,0 +1,6 @@
+---
+title: Content
+lastUpdate: true
+---
+
+Example page

packages/starlight/__e2e__/fixtures/ssr/src/content/docs/demo.mdx

@@ -0,0 +1,8 @@
+---
+title: Server Check
+lastUpdate: true
+---
+
+import ServerCheck from '../../component/ServerCheck.astro';
+
+<ServerCheck />

packages/starlight/__e2e__/fixtures/ssr/src/content/docs/index.md

@@ -0,0 +1,18 @@
+---
+title: Home Page
+template: splash
+lastUpdate: true
+hero:
+  title: Make your docs shine with Starlight
+  tagline: Everything you need to build a stellar documentation website. Fast, accessible, and easy-to-use.
+  actions:
+    - text: Get started
+      icon: right-arrow
+      variant: primary
+      link: /getting-started/
+    - text: View on GitHub
+      icon: external
+      link: https://github.com/withastro/starlight
+---
+
+Home page content

packages/starlight/__e2e__/git.test.ts

@@ -0,0 +1,36 @@
+import { makeTestRepo } from '../__tests__/git-utils';
+import { expect, testFactory } from './test-utils';
+import { rm } from 'node:fs/promises';
+import { fileURLToPath } from 'node:url';
+import { join } from 'node:path';
+
+const repoPath = fileURLToPath(new URL('./fixtures/git/', import.meta.url));
+
+const test = testFactory(repoPath);
+
+test.beforeAll(async () => {
+	// Clears existing nested repo to account for previously interrupted tests.
+	await rm(join(repoPath, '.git'), { recursive: true, force: true });
+	const testRepo = makeTestRepo(repoPath);
+
+	testRepo.commitAllChanges('Add home page', '2024-02-03');
+});
+
+test.afterAll(async () => {
+	// Remove nested repo after test runs
+	await rm(join(repoPath, '.git'), { recursive: true, force: true });
+});
+
+test('include last updated date from git in the footer', async ({ page, getProdServer }) => {
+	const starlight = await getProdServer();
+	await starlight.goto('/');
+
+	await expect(page.locator('footer')).toContainText('Last updated: Feb 3, 2024');
+});
+
+test('include git information while developing', async ({ page, makeServer }) => {
+	const starlight = await makeServer('dev', { mode: 'dev' });
+	await starlight.goto('/');
+
+	await expect(page.locator('footer')).toContainText('Last updated: Feb 3, 2024');
+});

packages/starlight/__e2e__/ssr.test.ts

@@ -0,0 +1,66 @@
+import { expect, testFactory } from './test-utils';
+import assert from 'node:assert';
+import { parseHTML } from 'linkedom';
+
+const test = testFactory('./fixtures/ssr/');
+
+test.beforeEach(() => {
+	delete process.env.STARLIGHT_PRERENDER;
+});
+
+test('Render page on the server', async ({ page, getProdServer }) => {
+	const starlight = await getProdServer();
+	await starlight.goto('/demo');
+
+	await expect(page.locator('#server-check')).toHaveText('On server');
+});
+
+test('Render 404 page on the server', async ({ page, getProdServer }) => {
+	const starlight = await getProdServer();
+	await starlight.goto('/not-found');
+
+	await expect(page.locator('#server-check')).toHaveText('On server');
+});
+
+test('SSR mode renders the same content page as prerendering', async ({
+	getProdServer,
+	makeServer,
+}) => {
+	const starlight = await getProdServer();
+	const ssrContent = await starlight.goto('/content').then((res) => res?.text());
+	assert(ssrContent);
+
+	process.env.STARLIGHT_PRERENDER = 'yes';
+	const prerenderStarlight = await makeServer('prerender');
+	const prerenderContent = await prerenderStarlight.goto('/content').then((res) => res?.text());
+	assert(prerenderContent);
+
+	expectEquivalentHTML(prerenderContent, ssrContent);
+});
+
+test('SSR mode renders the same splash page as prerendering', async ({
+	getProdServer,
+	makeServer,
+}) => {
+	const starlight = await getProdServer();
+	const ssrContent = await starlight.goto('/').then((res) => res?.text());
+	assert(ssrContent);
+
+	process.env.STARLIGHT_PRERENDER = 'yes';
+	const prerenderStarlight = await makeServer('prerender');
+	const prerenderContent = await prerenderStarlight.goto('/').then((res) => res?.text());
+	assert(prerenderContent);
+
+	expectEquivalentHTML(prerenderContent, ssrContent);
+});
+
+function expectEquivalentHTML(a: string, b: string) {
+	expect(getNormalizedHTML(a)).toEqual(getNormalizedHTML(b));
+}
+
+function getNormalizedHTML(html: string) {
+	const window = parseHTML(html);
+	window.document.querySelectorAll('script[src]').forEach((el) => el.setAttribute('src', ''));
+	window.document.querySelectorAll('link[href]').forEach((el) => el.setAttribute('href', ''));
+	return window.toString();
+}