Fix bail not being defined for the vite builder

[joshwooding]

Issue: #19349

Equivalent to storybookjs/builder-vite#510

What I did

How to test

• Is this testable with Jest or Chromatic screenshots?
• Does this need a new example in the kitchen sink apps?
• Does this need an update to the documentation?

If your answer is yes to any of these, please make sure to include it in your PR.

[IanVS]

This looks good, but let's see how #19406 plays out, because we might not need this change.

[JReinhold]

@joshwooding @IanVS in #19406 I agreed with @ndelangen that we would keep the bail in the return of preview builders because we expect to use them later when we want to shutdown the server more gracefully. But we didn't think the direct export of bail was necessary as it was only used in tests, but judging from the issue this solves I don't think that's correct.

So in short, we'll keep bail for now and this PR can move on.

[JReinhold]

Nit: In theory server can be undefined here - although I can't see if it can in practice right now.

To be defensive I'd change the type to be let server: ViteDevServer | undefined; and add optional chaining when using it.

[IanVS]

Would you want that in order to avoid the console warning? (this is in a try/catch.) I think it might be nice to show it, so we know what's happening, but it's also not super actionable, so I could go either way.

[JReinhold]

Hmmm good point, I actually have no strong preference.

[joshwooding]

I considered this but I chose to leave it unguarded so that it would throw and error.