fix: escape replacements in clientInjections

[d-fischer]

Description

This fixes a bug where special regex replacement characters are wrongly replaced. This can easily break a build. For example, this configuration always fails to compile:

import { defineConfig } from "vite";

export default defineConfig({
  define: {
    VAR_FOO: '"$`"'
  }
});

I also added the same fix to all other replacements in the same block of code, just to be extra sure.

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[patak-dev]

Thanks for the PR @d-fischer. We are discussing with @bluwy about performance on internal plugins, so I pushed a commit here to take the opportunity to gain some ms after your changes.

@bluwy testing with https://github.com/antfu/icones and DEBUG="vite:plugin-transform" pnpm dev, I'm getting ~100ms for the 3 times vite:client-inject is called on my machine. For both main and after this PR without my modifications. If there is a regression in perf because of these changes it would be hard to measure.

After vitejs/vite@27bf6dd (#12486), the transform can be a sync function, and it is now reporting ~0.3ms for the 3 calls. The buildStart got a new async function in its way, but I measured the time to run the internal logic and it is around consistently ~5ms. Maybe it is easier to optimize the new injectConfigValues. I think having one less async transform function is good in general as this hook will be called for every module. I think we should also extract the regex for the other branch. I'll do that in another PR.

[patak-dev]

Ah, nice one @d-fischer, I missed this one vitejs/vite@7e46ca2 (#12486) ❤️

[bluwy]

NIce! I might've wrongly remembered the speed for client-inject before, but I can confirm this PR helps a lot too. It would be nice if buildStart doesn't block the server startup too, but given it's only 2-4ms , I'm fine with it for now too.