feat: use signal-exit to handle shutdown

[jamesopstad]

Summary

Replaces Vite's ad-hoc signal handling (process.once('SIGTERM')) with signal-exit (https://github.com/tapjs/signal-exit) for shutdown of the dev and preview servers. signal-exit covers the full set of exit signals (SIGINT/Ctrl+C, SIGTERM, etc.) and intercepted process.exit() calls through a single, well-tested code path, and coordinates across separately-bundled copies (e.g. Vite's and Rolldown's) via a shared globalThis registry so callbacks fire exactly once. The existing stdin-end handling is retained (see below), since signal-exit does not cover it.

Stacked on #23110.

Notes

stdin end

Keeps the process.stdin.on('end') listener (with the existing CI !== 'true' guard) that signal-exit does not cover. This handles the case where a parent process shuts Vite down by closing the pipe rather than sending a signal — common when Vite runs as a child of another dev tool (e.g. Phoenix/Elixir watchers), and the source of zombie-process reports (#5743, #19091).

Added fallback for WebContainers

signal-exit works by patching process.reallyExit, which is a no-op in WebContainers (e.g. StackBlitz). Since Vite currently uses plain process.on('SIGTERM') / process.stdin.on('end') listeners (which do fire there), migrating to signal-exit would silently drop exit cleanup in WebContainers. This adds a fallback that registers a plain process.on('exit') listener when process.versions.webcontainer is set, matching Rolldown's handling (https://github.com/rolldown/rolldown/blob/main/packages/rolldown/src/utils/signal-exit.ts).

Note that exit listeners run synchronously and the process terminates as soon as they return, so async cleanup (await server.close()) may not finish on this path. This is inherent to process.on('exit') and is the same trade-off Rolldown makes. It is still strictly better than the alternative, where signal-exit is a plain no-op in WebContainers and no cleanup runs at all.

[sapphi-red]

Checking rollup/rollup#3493 which is linked in that PR, it seems the code was reverted in rollup/rollup#5803 so probably we should do that later.

[sapphi-red]

I think it'd be better to use an e2e test instead. Either by adding a new playground similarly to playground/cli or spawning node here.

[sapphi-red]

Have you tested the repro in #15418?

[sapphi-red]

/ecosystem-ci run

[pkg-pr-new]

Open in StackBlitz

@vitejs/plugin-legacy

pnpm add https://pkg.pr.new/@vitejs/plugin-legacy@23159 -D

npm i https://pkg.pr.new/@vitejs/plugin-legacy@23159 -D

yarn add https://pkg.pr.new/@vitejs/plugin-legacy@23159.tgz -D

vite

pnpm add https://pkg.pr.new/vite@23159 -D

npm i https://pkg.pr.new/vite@23159 -D

yarn add https://pkg.pr.new/vite@23159.tgz -D

commit: f557329

[vite-ecosystem-ci]

📝 Ran ecosystem CI on 94cf41f: Open

suite	result	latest scheduled
astro	❌ failure	❌ failure
qwik	⏹️ cancelled	⏹️ cancelled
sveltekit	❌ failure	❌ failure
tanstack-start	✅ success	⏹️ cancelled
react-router	❌ failure	❌ failure
vitest	❌ failure	❌ failure

✅ nuxt, module-federation, quasar, marko, laravel, vike, storybook, analogjs, vite-plugin-react, unocss, waku, vite-plugin-vue, vuepress, vite-plugin-cloudflare, vite-setup-catalogue, vite-plugin-pwa, vite-plugin-rsc, vite-plugin-svelte, vitepress, vite-environment-examples

[jamesopstad]

I've tried the prerelease and unfortunately it doesn't work correctly so I'll convert this to draft.

Here's the AI analysis:

1. Symptom — closeServer hook doesn't run on Ctrl+C. Reproduces with plain vite dev and zero plugins.
2. Root cause — Two separately-bundled copies of signal-exit@4.1.0 each install a process.on('SIGINT') listener:

• Rolldown, at import time (rolldown/dist/index.mjs:9-14, setup.ts main-thread onExit() closing its trace subscriber).
• Vite, when the dev server starts (setupExitListener → onExit(parentExitCallback), node.js:3337).
  They share the global emitter (Symbol.for("signal-exit emitter")) so callbacks are deduped, but each SignalExit keeps its own #loaded/#sigListeners and unload() only removes its own listener.

3. Failure sequence on SIGINT (signal-exit handler, node.js:1554-1568):
4. Rolldown's handler runs first: listeners.length(2) === count(2) → unload()s itself (count→1), emit("exit") runs Vite's parentExitCallback, which returns true and starts the async runExitCallbacks → server.close() → closeServer hook (deferred to a microtask). emit returns true, Rolldown skips re-raise.
5. Vite's own handler still fires (never unloaded): now listeners.length(1) === count(1) → emit returns false (already emitted) → !ret → synchronous process.kill(pid, 'SIGINT'), which kills the process before the microtask runs server.close().
   Net: Vite's runExitCallbacks (node.js:3320-3327) was written to await async cleanup then re-raise — but the other copy's synchronous re-raise pre-empts it.