Patch @mdx-js/mdx to stop generating invalid JSX when

used with remark-shiki-twoslash.

@calebeby, who provided the workaround, is the king.

- mdx-js/mdx#2123
- mdx-js/mdx#2112

package.json

@@ -17,6 +17,7 @@
     "@astrojs/tailwind": "^2.0.2",
     "@fontsource/brygada-1918": "^4.5.11",
     "@fontsource/inter": "^4.5.13",
+    "@mdx-js/mdx": "^2.1.3",
     "astro": "^1.4.2",
     "astro-eslint-parser": "^0.6.2",
     "remark-shiki-twoslash": "^3.1.0",
@@ -43,6 +44,12 @@
         "rollup",
         "postcss"
       ]
+    },
+    "overrides": {
+      "@mdx-js/mdx": "2.1.3"
+    },
+    "patchedDependencies": {
+      "@mdx-js/mdx@2.1.3": "patches/@mdx-js__mdx@2.1.3.patch"
     }
   }
 }

patches/@mdx-js__mdx@2.1.3.patch

@@ -0,0 +1,23 @@
+diff --git a/lib/plugin/recma-jsx-rewrite.js b/lib/plugin/recma-jsx-rewrite.js
+index 1e82a1e41b18b16cb5d2f2a66b07e2d9544c55db..eb5286a273f095bedb693ec587917d6162164108 100644
+--- a/lib/plugin/recma-jsx-rewrite.js
++++ b/lib/plugin/recma-jsx-rewrite.js
+@@ -387,11 +387,13 @@ export function recmaJsxRewrite(options = {}) {
+               })
+             }
+
+-            statements.push({
+-              type: 'VariableDeclaration',
+-              kind: 'const',
+-              declarations
+-            })
++            if (declarations.length > 0) {
++              statements.push({
++                type: 'VariableDeclaration',
++                kind: 'const',
++                declarations
++              })
++            }
+           }
+
+           /** @type {string} */

posts/features/shiki-twoslash.mdx

@@ -1,3 +1,14 @@
 We're using [Shiki Twoslash](https://shikijs.github.io/twoslash/) to highlight
 TypeScript and JavaScript code.
-`
+
+```ts twoslash
+// @module: esnext
+// @filename: maths.ts
+export function absolute(num: number) {
+  if (num < 0) return num * -1;
+  return num;
+}
+// @filename: index.ts
+import { absolute } from "./maths";
+const value = absolute(-1);
+```