Three IMAP connection leaks were recently fixed via try/finally
(#1325, #1330, #1423). This commit applies the same pattern to the
remaining callsites that still used inline logout-only cleanup.
routes/email_helpers.py:
- _fetch_sender_thread_context: conn was uninitialized when the outer
try/except returned early on connect failure, causing the finally
block to crash on conn.close()/conn.logout(). Merged the two
separate try blocks into one and added conn=None guard.
- _pre_retrieve_context: ctx_conn.logout() was inside the loop body
with no finally, so any exception in the folder/search loop leaked
the socket. Moved cleanup into a finally block with ctx_conn=None
guard.
mcp_servers/email_server.py:
- _list_emails: multiple inline conn.logout() calls on early-return
paths; exception between them leaked the socket. Wrapped in
try/finally.
- _read_email: same pattern — four separate logout() calls replaced
by a single finally block.
- _reply_to_email: logout() called before the error check, so an
exception in conn.select() leaked the socket. Wrapped in
try/finally.
- _download_attachment: same pattern as _reply_to_email.
Also adds tests/test_imap_leak_fixes.py with 9 regression tests (one
per function/failure-mode) that monkeypatch _imap_connect and assert
conn.logout() is called exactly once even when IMAP operations raise.
This file documents the shared test helpers and the review expectations that go
with them. The suite is being refactored incrementally, so this is a working
reference for that effort — not a claim that the suite is already fully
organized. Read it before adding a new helper or before reviewing a PR that
touches tests/helpers/.
Core principles
Keep PRs small and homogeneous: one kind of change per PR.
Prefer explicit local setup over hidden global fixtures.
Avoid expanding the root conftest.py unless absolutely necessary.
Do not mix file moves with logic changes in the same PR.
Do not weaken tests with skip/xfail just to make CI pass.
Validate the focused files you changed, plus any neighboring or
order-sensitive groups they interact with.
Helper conventions
The helpers below live under tests/helpers/. They exist to remove repeated
boilerplate that already appeared across multiple tests. Reach for one only when
your test matches its intended use; do not stretch a helper to cover a new case.
tests.helpers.cli_loader.load_script
Use when a test needs to import a script under scripts/ without repeating
SourceFileLoader / importlib.util boilerplate.
Intended for script/CLI tests that load a single file from scripts/.
Not for arbitrary package imports — use a normal import for those.
When migrating an existing test to it, keep the existing stubs and assertions
unchanged. Any sys.modules stubs the script needs at import time must still
be injected (e.g. via monkeypatch) before calling load_script.
tests.helpers.import_state.clear_module
Use when a test must drop one cached module and its parent-package attribute
before a fresh import.
Clears sys.modules[name].
Clears the parent-package attribute when present.
Good replacement for local sys.modules.pop(...) + delattr(parent, child)
blocks.
tests.helpers.import_state.preserve_import_state
Use when a test temporarily installs stubs into sys.modules and needs
deterministic cleanup afterward.
Context manager: restores both sys.modules entries and parent-package
attributes on exit (normal or exception).
Useful around module-level stubs or temporary imports.
Prefer narrow, explicit module names over broad ones.
Lucas Daniel
34bd8f0491