Vue loader bug with class field

[snigle]

Version

16.0.0-beta.8

Reproduction link

https://github.com/snigle/vue3Webpack

Steps to reproduce

Create webpack project from scratch with vue@next and vue-loader@next.
Make project working with simple vue component single file.
Declare a typescript class in the <script lang="ts">
Compilation will fail

What is expected?

compilation OK

What is actually happening?

ERROR in ./src/App.vue?vue&type=template&id=7ba5bd90&bindings=undefined (./node_modules/vue-loader/dist/templateLoader.js??ruleSet[1].rules[1]!./node_modules/vue-loader/dist/index.js??ruleSet[1].rules[3].use[0]!./src/App.vue?vue&type=template&id=7ba5bd90&bindings=undefined)
Module build failed (from ./node_modules/vue-loader/dist/templateLoader.js):
SyntaxError: Unexpected token u in JSON at position 0

---

I put a simple application in my repo to reproduce

[snigle]

the code which break is here :
https://github.com/snigle/vue3Webpack/blob/main/src/App.vue

<script lang="ts">
import {defineComponent, ref} from "vue";
// This class break the webpack vue-loader
class Test {
    myTest = "ok"
}
export default defineComponent({
// ...
});
</script>

[haoqunjiang]

Fixed in beta.9