fix: respect top-level server.preTransformRequests

[hi-ogawa]

Description

• Closes How to disable Pre-transform error log? vitest-dev/vitest#7345

It looks like there were two changes related to preTransformRequests on Vite 6, namely:

• server.preTransformRequests has no effect on environment.dev.preTransformRequests.
• while server.preTransformRequests: true by default both on client and ssr on Vite 5, now only client environment dev.preTransformRequests: true and ssr does not pre transform by default.

I made a reproduction in https://github.com/hi-ogawa/reproductions/tree/main/vitest-7345-preTransformRequests-false.

I assume the first one is a bug since currently server.preTransformRequests is no-op and we should either deprecate/remove or use it as a default. This is what this PR addresses and I confirmed this fixed Vitest's issue https://stackblitz.com/edit/bolt-vue-7wha3d5d?file=package.json. There are also some usages in the wild https://github.com/search?q=preTransformRequests&type=code.

For the 2nd one, I wasn't aware of this change and I'm not sure if it's intended. I'll leave this part out of the PR for now.

[pkg-pr-new]

Open in Stackblitz

npm i https://pkg.pr.new/vite@19272

commit: 0e056cc

[sapphi-red]

• server.preTransformRequests has no effect on environment.dev.preTransformRequests.

Checking the reason why this options was introduced (#6309), maybe it makes sense to sync the value with environments.client.dev.preTransformRequests inside instead of the default value for all environments.*.dev.preTransformRequests? It feels like there won't be a case where you want to enable/disable it for all the environments.

• while server.preTransformRequests: true by default both on client and ssr on Vite 5, now only client environment dev.preTransformRequests: true and ssr does not pre transform by default.

I didn't find any links, but I think this was a intentional change.

[patak-dev]

Let's merge this fix for now. I also think the change to only pre transform for the client was intentional but I can't find now a reference for that. We should change that default in another PR if we think that is needed. For environments running in different processes, maybe we have the same peformance profile as with the browser requesting modules. I don't recall us doing profiling for different cases with and without preTransformRequests for SSR. But Vitest disables it for performance reasons IIRC.

[sapphi-red]

I noticed I had a typo in the previous message (I wrote inside instead of instead 🤦).