`undef` error in `<script setup>` breaks HMR

[abitwhy]

Describe the bug

Any undef error in the <script setup> will break the HMR. If auto save file is on, then entering any incomplete code will cause an error and break the HMR.

Break means it no longer working, even if correct the code. And only fresh the page will make HMR work. This happened only recently, and only happened in <script setup> .

Reproduction

https://vite.new/vue

Reproduce Steps

1. Open a new Vite-Vue project (click the reproduction link above)
2. Open src/App.vue
3. Write an undef error in <script setup> (For example, write some characters in a new line)

System Info

N/A

Used Package Manager

npm

Logs

No response

Validations

• [X] Follow our Code of Conduct
• [X] Read the Contributing Guidelines.
• [X] Read the docs.
• [X] Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• [X] Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• [X] Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• [X] The provided reproduction is a minimal reproducible example of the bug.

[github-actions[bot]]

Hello @abitwhy. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with need reproduction will be closed if they have no activity within 3 days.

[sapphi-red]

I tested with https://vite.new/vue but didn't happen.

Would you write the steps to reproduce?

[abitwhy]

@sapphi-red The reproduce steps were added in the top comment.

[sapphi-red]

Please write more concrete steps. I'm still not able to reproduce. I edited HelloWorld.vue in the following steps.

1. <script setup>
   import { ref } from 'vue'
   
   defineProps({
     msg: String
   })
   
   const count = ref(0)
   </script>

2. <script setup>
   import { ref } from 'vue'
   
   defineProps({
     msg: String
   })
   
   const count = ref(0)
   
   console.log(
   </script>

3. <script setup>
   import { ref } from 'vue'
   
   defineProps({
     msg: String
   })
   
   const count = ref(0)
   
   console.log()
   </script>

[abitwhy]

Check this:

[abitwhy]

After more testing, I found that only no-undef error will case this bug.

[sapphi-red]

I was able to reproduce 👍