fix(browser): fix updating snapshot during watch mode

[hi-ogawa]

Description

Closes #4865

It might be a little tough to automate a test for this but I'll try something.

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[sheremet-va]

This seems sketchy. What if exitCode was mutated by node:test? Why Vitest mutates exitCode?

[hi-ogawa]

I didn't investigate much but I meant to do something similar as runVitest test util here:

vitest/test/test-utils/index.ts

Lines 40 to 42 in 044c738

	exitCode = process.exitCode
	process.exitCode = 0
	process.exit = exit

I'll look into more detail what exactly is happening with exit code.

[hi-ogawa]

I refined some assertions to be more precise about process.exitCode d2366e8

Why Vitest mutates exitCode?

Vitest sets process.exitCode = 1 whenever test failed during runtFiles:

vitest/packages/vitest/src/node/core.ts

Lines 505 to 506 in d2366e8

	if (hasFailed(files))
	process.exitCode = 1

EDIT: I further refactored by introducing wrapWithExitCode utility ccfa85a

[hi-ogawa]

test/browser/specs/fix-4686.test.mjs (added in #4692) became flaky on playwright/webkit. I don't see other PRs having problems, so most likely addition of new test here is affecting it. I'll debug and try something to make it less flaky.

[hi-ogawa]

Actually I also need to be careful with automatic process.exit by webdriverio:

vitest/packages/browser/src/node/providers/webdriver.ts

Lines 93 to 95 in 3d18efd

	// TODO: right now process can only exit with timeout, if we use browser
	// needs investigating
	process.exit()

Test flaky etc... there are a few things to work out, so I'll put my PRs back to draft.

[sheremet-va]

Thanks!