diff --git a/fixtures/input/astro.astro b/fixtures/input/astro.astro
index df4e8e5ef7..21812eabe2 100644
--- a/fixtures/input/astro.astro
+++ b/fixtures/input/astro.astro
@@ -18,4 +18,21 @@ const content = "hi!";
   document.querySelector('h1')?.addEventListener('click', () => {
         logger('clicked');
   });
+
+  function someFunction() {
+    const theme = (() => {
+      if (
+        typeof localStorage !== 'undefined' && localStorage.getItem('theme')
+      ) {
+        return localStorage.getItem('theme')
+      }
+    })()
+    if (theme === 'light') {
+      document.documentElement.classList.remove('dark')
+    } else {
+      document.documentElement.classList.add('dark')
+    }
+    return
+  }
+  someFunction()
 </script>
diff --git a/fixtures/output/all/astro.astro b/fixtures/output/all/astro.astro
index b67c6784ea..74563cbf56 100644
--- a/fixtures/output/all/astro.astro
+++ b/fixtures/output/all/astro.astro
@@ -18,4 +18,22 @@ const { log: logger } = console
 document.querySelector('h1')?.addEventListener('click', () => {
   logger('clicked')
 })
+
+function someFunction() {
+  const theme = (() => {
+    if (
+      typeof localStorage !== 'undefined' 
+      && localStorage.getItem('theme')
+    ) {
+      return localStorage.getItem('theme')
+    }
+  })()
+  if (theme === 'light') {
+    document.documentElement.classList.remove('dark')
+  }
+  else {
+    document.documentElement.classList.add('dark')
+  }
+}
+someFunction()
 </script>