Vue2.insertAdjacentElement is not a function

[kingyue737]

Describe the bug

I imported a Vue 2 component library in vitest. The test should pass but it throws the following TypeError:

Vue2.insertAdjacentElement is not a function

I don't know whether it is a bug of vite, vitest or jsdom. Since there is no such issue when Vite <= 3.1.4, I post this bug here.

Reproduction

https://stackblitz.com/edit/vitest-dev-vitest-lhw5je

Steps to reproduce

Open the link and wait for the test to fail

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (6) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 16.14.2 - /usr/local/bin/node
    Yarn: 1.22.10 - /usr/local/bin/yarn
    npm: 7.17.0 - /usr/local/bin/npm
  npmPackages:
    vite: ^3.1.6 => 3.1.6

Used Package Manager

pnpm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• 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.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

Changing the vue-echarts alias from vue-echarts/dist/index.esm.min.js to vue-echarts/dist/index.esm.js worked.
Also reverting #10300 (effb7c3) from v3.1 branch worked.

/cc @bluwy

[bluwy]

Thanks for finding the cause sapphi. #10388 should fix this issue as var declarations was accidentally treated as block-scoped instead of function-scoped in #10300