tsconfig has no effect on postcss.config.ts

[kingyue737]

Describe the bug

In tsconfig.json, esModuleInterop flag is set. But postcss.config.ts cannot import module declared with export =

Reproduction

https://stackblitz.com/edit/vitejs-vite-vwdwgx

Steps to reproduce

Open the reproduction link

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:
    @vitejs/plugin-vue2: ^1.1.2 => 1.1.2 
    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]

Vite just uses postcss-load-config and it happens with it too.
https://stackblitz.com/edit/vitejs-vite-5p4wnp?file=p.mjs

Maybe it's a limitation/bug of postcss-load-config or ts-node.

[haoqunjiang]

TypeStrong/ts-node#1057 ts-node doesn't support solution-style tsconfig.