feat: backport treat Astro file scripts as TS (#8151)

Author: matthewp

packages/playground/optimize-deps/index.astro

@@ -0,0 +1,4 @@
+<script>
+  type Foo = 'bar';
+  console.log("stuff");
+</script>

packages/playground/optimize-deps/index.html

@@ -119,6 +119,8 @@ <h2>Reused variable names</h2>
 
   import { parse } from 'node:url'
   text('.url', parse('https://vitejs.dev').hostname)
+
+  import './index.astro'
 </script>
 
 <script type="module">

packages/playground/optimize-deps/vite.config.js

@@ -50,6 +50,15 @@ module.exports = {
           res.end('pong')
         })
       }
+    },
+    {
+      name: 'test-astro',
+      transform(code, id) {
+        if (id.endsWith('.astro')) {
+          code = `export default {}`
+          return { code }
+        }
+      }
     }
   ]
 }

packages/vite/src/node/optimizer/scan.ts

@@ -281,6 +281,8 @@ function esbuildScanPlugin(
             let loader: Loader = 'js'
             if (lang === 'ts' || lang === 'tsx' || lang === 'jsx') {
               loader = lang
+            } else if (path.endsWith('.astro')) {
+              loader = 'ts'
             }
             const srcMatch = openTag.match(srcRE)
             if (srcMatch) {