feat: move MDX into the processors themselves (#17262)

Co-authored-by: Armand Philippot <git@armand.philippot.eu>

Author: Princesseuh

.changeset/astro-markdown-remark-peer-range.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes `@astrojs/markdown-remark` being pinned to an exact version.

.changeset/internal-helpers-mdx-export.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/internal-helpers': minor
+---
+
+Adds an `@astrojs/internal-helpers/mdx` entrypoint with the shared helpers the Markdown processor packages use to render `.mdx` files.

.changeset/markdown-processors-own-mdx.md

@@ -0,0 +1,8 @@
+---
+'@astrojs/markdown-remark': minor
+'@astrojs/markdown-satteri': minor
+---
+
+Adds MDX rendering to the `unified()` and `satteri()` processors.
+
+Both processors now compile `.mdx` files themselves. You still need to install `@astrojs/mdx` to add MDX support to your project.

.changeset/mdx-extend-markdown-config-processor.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/mdx': patch
+---
+
+Fixes `.mdx` files still using `markdown.processor` when `extendMarkdownConfig` is `false`. They now use a clean default processor instead; pass `mdx({ processor })` to choose one explicitly.

.changeset/mdx-legacy-plugin-options-warning.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/mdx': patch
+---
+
+Adds a warning when the deprecated `remarkPlugins`, `rehypePlugins`, `recmaPlugins` and `remarkRehype` options are ignored because your Markdown processor does not run them. They still apply when your processor is `unified()`, and were previously dropped silently otherwise.

.changeset/mdx-processor-version-requirements.md

@@ -0,0 +1,15 @@
+---
+'@astrojs/mdx': major
+---
+
+Moves MDX file processing to the Markdown processors.
+
+'@astrojs/mdx' is still required to add MDX support to your project. However, it now delegates the MDX files processing to Markdown processors.
+
+#### What should I do?
+
+If you haven't explicitly installed a Markdown processor, you don't need to do anything.
+
+Otherwise, ensure that your configured Markdown processor uses the following version:
+- `@astrojs/markdown-satteri` 0.4.0 or later if you use `satteri()`
+- `@astrojs/markdown-remark` 7.3.0 or later if you use `unified()`

.changeset/unified-recma-plugins.md

@@ -0,0 +1,5 @@
+---
+'@astrojs/markdown-remark': minor
+---
+
+Adds a `recmaPlugins` option to `unified()` for adding recma (estree/JSX) plugins to the MDX compiler.

knip.js

@@ -126,9 +126,8 @@ export default {
 		'packages/integrations/mdx': {
 			entry: [srcEntry, dtsEntry, testEntry],
 			project,
-			// Optional peer dep: type-only imports for narrowing the `satteri()` processor.
-			// Knip flags it because the peer is referenced from source; the runtime stays gated by name-check.
-			ignoreDependencies: ['@astrojs/markdown-satteri'],
+			// Optional peer dep: dynamically imported for the deprecated remark/rehype options.
+			ignoreDependencies: ['@astrojs/markdown-remark'],
 		},
 		'packages/markdown/remark': {
 			entry: [srcEntry, dtsEntry, testEntry],
@@ -137,6 +136,8 @@ export default {
 		'packages/markdown/satteri': {
 			entry: [srcEntry, dtsEntry, testEntry],
 			project,
+			// Only referenced by a `declare module 'hast'` augmentation, which knip doesn't count.
+			ignoreDependencies: ['@types/hast'],
 		},
 		'packages/upgrade': {
 			entry: ['src/index.ts!', testEntry],

packages/astro/package.json

@@ -182,7 +182,7 @@
     "sharp": "^0.35.4"
   },
   "peerDependencies": {
-    "@astrojs/markdown-remark": "workspace:*"
+    "@astrojs/markdown-remark": "^7.3.0"
   },
   "peerDependenciesMeta": {
     "@astrojs/markdown-remark": {

packages/astro/src/core/util.ts

@@ -1,4 +1,3 @@
-import fs from 'node:fs';
 import { fileURLToPath } from 'node:url';
 import type { AstroSettings } from '../types/astro.js';
 import type { AstroConfig } from '../types/public/config.js';
@@ -132,51 +131,6 @@ export function isEndpoint(file: URL, settings: AstroSettings): boolean {
 	return !endsWithPageExt(file, settings) && !file.toString().includes('?astro');
 }
 
-export function resolveJsToTs(filePath: string) {
-	if (filePath.endsWith('.jsx') && !fs.existsSync(filePath)) {
-		const tryPath = filePath.slice(0, -4) + '.tsx';
-		if (fs.existsSync(tryPath)) {
-			return tryPath;
-		}
-	}
-	return filePath;
-}
-
-// Match Vite's default `resolve.extensions` order so that when multiple
-// candidate files exist, we pick the same module Vite will load.
-// https://vite.dev/config/shared-options.html#resolve-extensions
-const VITE_DEFAULT_RESOLVE_EXTENSIONS = ['.mjs', '.js', '.mts', '.ts', '.jsx', '.tsx', '.json'];
-
-/**
- * Resolve a path that doesn't name a file on disk (e.g. produced by an
- * extensionless import like `import { Counter } from './Counter'`) to the file
- * Vite would load, by probing Vite's default extension order and directory
- * `index` files. Returns the path unchanged when it already exists as a file
- * or when no candidate is found.
- */
-export function resolveExtensionlessPath(filePath: string): string {
-	const stat = fs.statSync(filePath, { throwIfNoEntry: false });
-	if (stat?.isFile()) {
-		return filePath;
-	}
-	for (const ext of VITE_DEFAULT_RESOLVE_EXTENSIONS) {
-		const tryPath = filePath + ext;
-		if (fs.existsSync(tryPath)) {
-			return tryPath;
-		}
-	}
-	// Directory import: resolve to its `index` module, like Vite does.
-	if (stat?.isDirectory()) {
-		for (const ext of VITE_DEFAULT_RESOLVE_EXTENSIONS) {
-			const tryPath = `${filePath}/index${ext}`;
-			if (fs.existsSync(tryPath)) {
-				return tryPath;
-			}
-		}
-	}
-	return filePath;
-}
-
 /**
  * Set a default NODE_ENV so Vite doesn't set an incorrect default when loading the Astro config
  */