fix(runner): long synchronous tasks does not time out (fix #2920)

[ferdodo]

Description

Fixes #2920

This PR solves Vitest ignoring timeouts on long synchronous tasks, that are blocking until the task and the timeout are settled simultaneously.

In this case we want to give priority to the timeout, because a test running longer than it's own timeout shall fail.

• The result of the test is wrapped into a promise, and delayed to be processed in the same event loop cycle as the timeout.
• I changed the order in the Promise.race, to give the timeout priority over the other promise.
• I added a test for this case that takes 15ms, both changes are necessary to make the test pass.
• Using nextTick from getSafeTimers() over the additional setTimeout I used did not solve the issue.
• Outputing logs during tests displays slighly differently.

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Tests

• Run the tests with pnpm test:ci.

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[hi-ogawa]

Nice find! The change makes sense to me.

[hi-ogawa]

It took a while to understand this but the idea is more or less like this? Executing fn in sync as usual, but holding off returning until setTimeout(.., 0) to flush other setTimeout callbacks. I think code is fine as is, but it's just my commentary.

      (async () => {
        const result = await fn(...args);
        await new Promise(resolve => setTimeout(resolve, 0))
        return result;
      })()

Oh, well it looks like this code actually breaks test.extend, so I'm not sure I understood this well 😅 Ah I forgot about args

[ferdodo]

Thanks a lot! Yes that's the same thing, I can try refactor with your code if it's best.

[ferdodo]

The Browser: webkit test was passing in one of my previous run:

https://github.com/vitest-dev/vitest/actions/runs/11955759654

Is it a flakiness issue ? It might just need a job re-run to pass.

[Edit]: Just re-pushed an identical commit to trigger the re-run. Test are passing now ✅