PluginContext missing `fs` in serve/dev mode

[lukeed]

Describe the bug

The PluginContext types say that this.fs should exist in plugin hooks like transform or buildStart but it's undefined during dev/serve mode.

Unlike this.emitFile, it does not print a warning message in its place either.

Reproduction

https://stackblitz.com/edit/vitejs-vite-tqyjuqpn?file=index.html,src%2Fmain.ts,vite.config.ts%3AL8&terminal=dev

Steps to reproduce

No response

System Info

vite @ 6.3.5

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.

[hi-ogawa]

this.fs is the latest rollup feature and not implemented on Vite dev server yet. Closing in favor of #20200