Cannot use <script setup lang="ts"> in markdown file

[olivervorasai]

Describe the bug

Using script setup with lang="ts" causes [plugin:vite:vue] [@vue/compiler-sfc] <script> and <script setup> must have the same language type. error. The error does not occur if lang="ts" is removed.

#575 is the same issue except a reproduction is included in this issue.

Reproduction

Minimal reproduction available here: https://github.com/olivervorasai/vitepress-starter-ts-bug

1. npm install
2. npm run docs:dev

This reproduction was creating using the following documentation:

• https://vitepress.vuejs.org/guide/getting-started.html#step-1-create-a-new-project
• https://vitepress.vuejs.org/guide/using-vue.html#using-components

Expected behavior

Vitepress should render with or without lang="ts".

System Info

System:
    OS: Windows 10 10.0.19043
    CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
    Memory: 9.27 GB / 15.85 GB
  Binaries:
    Node: 16.13.1 - C:\Program Files\nodejs\node.EXE
    npm: 8.3.1 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (101.0.1210.53)
    Internet Explorer: 11.0.19041.1566
  npmPackages:
    vitepress: ^1.0.0-alpha.1 => 1.0.0-alpha.1

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.

[kecrily]

See #667 (comment)

[brc-dd]

As stated by the error: <script> and <script setup> must have the same language type. We inject a <script> block by default to each md file. But since not everyone uses TS, it doesn't has lang set to ts.

As a workaround, add empty <script> block with lang="ts" to your md file:

<script lang="ts"></script>