Markdoc - improve syntax highlighting support (#7209)

* feat: prism and shiki support, with better exports!

* chore: update tests

* chore: fix lock

* chore: add prism test

* chore: remove `async` from prism

* docs: update syntax highlight readme

* chore: changeset

* edit: remove `await` from prism docs

* chore: update old changest with new shiki instructions

* fix: add trailing newline on ts-expect-error

* refactor: resolve promises internally

* docs: remove `await` from shiki examples

1 files changed, 24 insertions, 0 deletions

diff --git a/packages/integrations/markdoc/src/extensions/prism.ts b/packages/integrations/markdoc/src/extensions/prism.ts
new file mode 100644
index 000000000..e28112c9a
--- /dev/null
+++ b/packages/integrations/markdoc/src/extensions/prism.ts
@@ -0,0 +1,24 @@
+// leave space, so organize imports doesn't mess up comments
+// @ts-expect-error Cannot find module 'astro/runtime/server/index.js' or its corresponding type declarations.
+import { unescapeHTML } from 'astro/runtime/server/index.js';
+
+import { runHighlighterWithAstro } from '@astrojs/prism/dist/highlighter';
+import { Markdoc, type AstroMarkdocConfig } from '../config.js';
+
+export default function prism(): AstroMarkdocConfig {
+	return {
+		nodes: {
+			fence: {
+				attributes: Markdoc.nodes.fence.attributes!,
+				transform({ attributes: { language, content } }) {
+					const { html, classLanguage } = runHighlighterWithAstro(language, content);
+
+					// Use `unescapeHTML` to return `HTMLString` for Astro renderer to inline as HTML
+					return unescapeHTML(
+						`<pre class="${classLanguage}"><code class="${classLanguage}">${html}</code></pre>`
+					);
+				},
+			},
+		},
+	};
+}