#25 fixed two sys.modules writes in test_auth_regressions.py that left empty
stub modules behind for the rest of the session, breaking 23 tests under one
collection order while the full suite stayed green. The class is wider than
that file, and an audit is the wrong answer to it: nothing stops the next one,
and the failure it causes lands on an unrelated test in a different file.
So this is a guard instead. An autouse fixture in the root conftest snapshots
which src.* / core.* names are bound to a bare ModuleType, and fails any test
that adds one. "Bare" is the same test the clear_fake_* helpers already use -
a plain types.ModuleType with no on-disk __file__. MagicMock stand-ins are out
of scope: they answer every attribute, so they fail at the point of use rather
than silently, and several files install them deliberately.
Three details that matter:
- It lives in the root conftest, so it is set up before any test-module
fixture and torn down after all of them. A stub a test's own teardown
removes is not reported.
- It drops the leaked entries as well as reporting them, so the failure stays
on the test that introduced it instead of cascading through the rest of the
run.
- It only reports stubs added during the test. Import state the session starts
with, including this conftest's own src.database stub, is left alone.
It found one beyond #25 on the first full run: _stub_heavy in
test_scheduler_restart_doublefire.py leaks the same five src.* modules as the
test #25 fixed, via sys.modules.setdefault. It already receives monkeypatch,
so the fix is to register through it. Fixed here because the guard has to land
green.
Full suite, macOS, default collection order:
this branch 10655 passed, 6 failed, 6 skipped 406s
lab 10655 passed, 6 failed, 6 skipped 371s
Same six either way, which is the point - none of this is visible in the
default order. Four are pre-existing macOS environment failures:
test_glob_confined_e2e and the two test_code_nav_tools document cases resolve
/tmp to /private/tmp, and
test_real_socket_falls_back_from_dead_first_to_live_second is connect-refused
timing on real sockets. The other two are the rich-colour and ffmpeg items
from the same ledger, fixed on their own branches.
Not verified: Linux, and any collection order other than the default. The
guard is order-independent by construction - it compares before and after
within a single test - but I have only run the default order.
Test-only refactor continuing #2523. Adds a shared import-state isolation helper with focused coverage and migrates two pilot tests that manually preserved sys.modules and parent package attributes.
Léo