fix: do not end server process in CI

[IanVS]

Description

This fixes a problem running the vite server in docker and github actions (ci) as documented in material-svelte/vite-web-test-runner-plugin#6. It took me a long time to figure out why my tests were completing just fine locally but exiting early with a 0 exit code in CI without running any tests. I eventually traced it down to the process.exit(0) added in #1857.

With the changes here, I am able to run tests successfully both locally, as well as in CI.

I would love if @nullpilot, @jonathanstiansen, and @1player could take a look and try this out to see if it meets their needs as well.

Additional context

Docker (and by extension github ci) do not always run as an interactive tty. Create-react-app had an issue when they tried to add a shutdown based on detecting an interactive terminal, and addressed it by only checking for a CI environment variable instead (see facebook/create-react-app#8845 and the referenced issue, facebook/create-react-app#8688).

As an aside, note that webpack-dev-server listens to both SIGINT and SIGTERM for docker support (webpack/webpack-dev-server#787), but SIGINT was factored out of vite and I'm not quite sure why based on the commit.

I'm also not sure how to write a test for this particular feature, but I did check that the server is still torn down when I run vite locally and then kill it with ctrl+c. I think it will also be interesting to see if CI completes successfully, since that was a problem the last time that process.stdin.resume() was added, which I've added here to match CRA and to allow the stream to drain correctly.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[IanVS]

Hi, does anyone have any thoughts on this? I'm using patch-package to apply this change in my own project, and it's working well, but it would be nice to avoid that.

[bmz1]

It would be great to run tests on CI with vite, and this is a huge blocker. I'm waiting for this as well.

[patak-dev]

@nullpilot this is going to affect Elixir Phoenix dev watcher if I understand correctly, but even with the fix in #1857 there were people still having issues. The issue with docker seems more important to fix. Further PRs improving this are welcome.