Update @astrojs/mdx to v3

.changeset/perfect-chicken-dream.md

@@ -0,0 +1,26 @@
+---
+'@astrojs/starlight': minor
+---
+
+Updates `@astrojs/mdx` to v3 and enables MDX optimization by default
+
+⚠️ **Potentially breaking change:** MDX optimization speeds up builds (Starlight’s docs are building ~40% faster for example), but restricts some advanced MDX features. See full details in the [MDX optimization documentation](https://docs.astro.build/en/guides/integrations-guide/mdx/#optimize).
+
+Most Starlight users should be unaffected, but if you are using MDX files outside of Starlight pages with the `components` prop, you may see issues. You can disable optimization by adding MDX manually to your `integrations` array in `astro.config.mjs`:
+
+```diff
+import { defineConfig } from 'astro/config';
++ import mdx from '@astrojs/mdx';
+import starlight from '@astrojs/starlight';
+
+// https://astro.build/config
+export default defineConfig({
+	integrations: [
+		starlight({
+			title: 'My docs',
+			// ...
+		}),
++		mdx(),
+	],
+});
+```

.changeset/stale-badgers-fetch.md

@@ -0,0 +1,11 @@
+---
+'@astrojs/starlight': minor
+---
+
+⚠️ **BREAKING CHANGE:** The minimum supported version of Astro is now 4.8.6
+
+Please update Astro and Starlight together:
+
+```sh
+npx @astrojs/upgrade
+```

docs/package.json

@@ -18,7 +18,7 @@
     "@astrojs/starlight": "workspace:*",
     "@lunariajs/core": "^0.0.32",
     "@types/culori": "^2.0.0",
-    "astro": "^4.3.5",
+    "astro": "^4.8.6",
     "culori": "^3.2.0",
     "sharp": "^0.32.5"
   },

examples/basics/package.json

@@ -12,7 +12,7 @@
   },
   "dependencies": {
     "@astrojs/starlight": "^0.22.4",
-    "astro": "^4.3.5",
+    "astro": "^4.8.6",
     "sharp": "^0.32.5"
   }
 }

examples/tailwind/package.json

@@ -14,7 +14,7 @@
     "@astrojs/starlight": "^0.22.4",
     "@astrojs/starlight-tailwind": "^2.0.2",
     "@astrojs/tailwind": "^5.1.0",
-    "astro": "^4.3.5",
+    "astro": "^4.8.6",
     "sharp": "^0.32.5",
     "tailwindcss": "^3.4.1"
   }

package.json

@@ -16,7 +16,7 @@
     "@changesets/changelog-github": "^0.4.8",
     "@changesets/cli": "^2.26.1",
     "@size-limit/file": "^8.2.4",
-    "astro": "^4.3.5",
+    "astro": "^4.8.6",
     "prettier": "^3.0.0",
     "prettier-plugin-astro": "^0.13.0",
     "size-limit": "^8.2.4",

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

@@ -4,6 +4,6 @@
   "private": true,
   "dependencies": {
     "@astrojs/starlight": "workspace:*",
-    "astro": "^4.3.5"
+    "astro": "^4.8.6"
   }
 }

packages/starlight/index.ts

@@ -63,10 +63,17 @@ export default function StarlightIntegration({
 					integrations.push(starlightSitemap(starlightConfig));
 				}
 				if (!allIntegrations.find(({ name }) => name === '@astrojs/mdx')) {
-					integrations.push(mdx());
+					integrations.push(mdx({ optimize: true }));
 				}
+
+				// Add integrations immediately after Starlight in the config array.
+				// e.g. if a user has `integrations: [starlight(), tailwind()]`, then the order will be
+				// `[starlight(), expressiveCode(), sitemap(), mdx(), tailwind()]`.
+				// This ensures users can add integrations before/after Starlight and we respect that order.
+				const selfIndex = config.integrations.findIndex((i) => i.name === '@astrojs/starlight');
+				config.integrations.splice(selfIndex + 1, 0, ...integrations);
+
 				updateConfig({
-					integrations,
 					vite: {
 						plugins: [vitePluginStarlightUserConfig(starlightConfig, config)],
 					},

packages/starlight/package.json

@@ -180,18 +180,18 @@
     "./style/markdown.css": "./style/markdown.css"
   },
   "peerDependencies": {
-    "astro": "^4.2.7"
+    "astro": "^4.8.6"
   },
   "devDependencies": {
     "@astrojs/markdown-remark": "^4.2.1",
     "@playwright/test": "^1.43.1",
     "@types/node": "^18.16.19",
     "@vitest/coverage-v8": "^1.6.0",
-    "astro": "^4.3.5",
+    "astro": "^4.8.6",
     "vitest": "^1.6.0"
   },
   "dependencies": {
-    "@astrojs/mdx": "^2.1.1",
+    "@astrojs/mdx": "^3.0.0",
     "@astrojs/sitemap": "^3.0.5",
     "@pagefind/default-ui": "^1.0.3",
     "@types/hast": "^3.0.3",

packages/starlight/utils/translations.ts

@@ -4,7 +4,9 @@ import type { i18nSchemaOutput } from '../schemas/i18n';
 import { createTranslationSystem } from './createTranslationSystem';
 
 type UserI18nSchema = 'i18n' extends DataCollectionKey
-	? CollectionEntry<'i18n'>['data']
+	? CollectionEntry<'i18n'> extends { data: infer T }
+		? T
+		: i18nSchemaOutput
 	: i18nSchemaOutput;
 
 /** Get all translation data from the i18n collection, keyed by `id`, which matches locale. */