This commit introduces a new --experimental-test-isolation flag
that, when set to 'none', causes the test runner to execute all
tests in the same process. By default, this is the main test
runner process, but if watch mode is enabled, it spawns a separate
process that runs all of the tests.
The default value of the new flag is 'process', which uses the
existing behavior of running each test file in its own child
process.
It is worth noting that when the isolation mode is 'none', globals
and all other top level logic (such as top level before() and after()
hooks) is shared among all files.
Co-authored-by: Moshe Atlow <moshe@atlow.co.il>
PR-URL: https://github.com/nodejs/node/pull/53927
Fixes: https://github.com/nodejs/node/issues/51548
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
