These are the only cases 100% safe to apply the renaming of the
testcase class names to match the file names.
All other cases are not safe, because they are missing namespace
and may enter into name conflicts. Adding namespaces is not as
simple as imagined because it implies to, also, add a good number
of modifications to core. See the issue for more details.
While this is not strictly required, because removal will
happen in PHPUnit 9.0, we are already getting rid of all
uses in core.
From release notes:https://phpunit.de/announcements/phpunit-8.html
assertInternalType() is deprecated and will be removed in
PHPUnit 9. Refactor your test to use assertIsArray(), assertIsBool(),
assertIsFloat(), assertIsInt(), assertIsNumeric(), assertIsObject(),
assertIsResource(), assertIsString(), assertIsScalar(),
assertIsCallable(), or assertIsIterable() instead.