[Markdoc] Support automatic image optimization with `experimental.assets` (#6630)

* wip: scrappy implementation. It works! 🥳

* chore: add code comments on inline utils

* fix: code cleanup, run on experimental.assets

* feat: support ~/assets alias

* fix: spoof `astro:assets` when outside experimental

* test: image paths in dev and prod

* feat: support any vite alias with ctx.resolve

* fix: avoid trying to process absolute paths

* fix: raise helpful error for invalid vite paths

* refactor: revert URL support on emitAsset

* chore: lint

* refactor: expose emitESMImage from assets base

* wip: why doesn't assets exist

* scary chore: make @astrojs/markdoc truly depend on astro

* fix: import emitESMImage straight from dist

* chore: remove type def from assets package

* chore: screw it, just ts ignore

* deps: rollup types

* refactor: optimize images during parse step

* chore: remove unneeded `.flat()`

* fix: use file-based relative paths

* fix: add back helpful error

* chore: changeset

* deps: move astro back to dev dep

* fix: put emit assets behind flag

* chore: change to markdoc patch

1 files changed, 9 insertions, 1 deletions

diff --git a/packages/integrations/markdoc/components/TreeNode.ts b/packages/integrations/markdoc/components/TreeNode.ts
index b9b4c5c4d..f46355d5c 100644
--- a/packages/integrations/markdoc/components/TreeNode.ts
+++ b/packages/integrations/markdoc/components/TreeNode.ts
@@ -1,6 +1,8 @@
 import type { AstroInstance } from 'astro';
 import type { RenderableTreeNode } from '@markdoc/markdoc';
 import { createComponent, renderComponent, render } from 'astro/runtime/server/index.js';
+// @ts-expect-error Cannot find module 'astro:markdoc-assets' or its corresponding type declarations
+import { Image } from 'astro:markdoc-assets';
 import Markdoc from '@markdoc/markdoc';
 import { MarkdocError, isCapitalized } from '../dist/utils.js';
 
@@ -45,10 +47,16 @@ export const ComponentNode = createComponent({
 	propagation: 'none',
 });
 
+const builtInComponents: Record<string, AstroInstance['default']> = {
+	Image,
+};
+
 export function createTreeNode(
 	node: RenderableTreeNode,
-	components: Record<string, AstroInstance['default']> = {}
+	userComponents: Record<string, AstroInstance['default']> = {}
 ): TreeNode {
+	const components = { ...userComponents, ...builtInComponents };
+
 	if (typeof node === 'string' || typeof node === 'number') {
 		return { type: 'text', content: String(node) };
 	} else if (node === null || typeof node !== 'object' || !Markdoc.Tag.isTag(node)) {