Use idiomatic pytest features

Favor built-in pytest mechanisms over manual boilerplate to keep tests concise, correct, and properly isolated.

• Use pytest.raises(ExceptionType) instead of manual try/except blocks to assert that an exception is raised; don’t add code after the raising call that can never execute.
• Use shared fixtures (e.g. app, client, app_ctx) instead of re-creating a Flask app/context by hand in every test; be mindful of fixture scope so each test still gets the isolation it needs (e.g. separate app contexts when previously each test created its own).
• Use monkeypatch (or yield-based fixtures) for patching globals/env vars instead of mutating module attributes directly; always restore/clean up state, even if a later assertion fails, by doing the teardown after a yield in the fixture rather than returning a value.
• Use pytest.importorskip to skip tests cleanly when an optional dependency isn’t installed, rather than failing the whole suite.
• Use pytest.mark.parametrize to replace repetitive near-duplicate test functions/assertions with a single parametrized test; when parametrizing multiple related values, pass them as separate parameters (e.g. "args, expected") rather than bundling them into one tuple parameter.
• When a test touches external resources (temp files, signals, sockets), ensure proper cleanup: close/remove temp files (prefer tmp_path/NamedTemporaryFile with a with block over manual mkstemp), and use available context managers (e.g. Signal.connected_to) to connect/disconnect signals instead of manual try/finally.
• Don’t rely on non-deterministic ordering (e.g. iterating a set) in assertions; sort or otherwise normalize the data before comparing.

Example, converting a manual exception check to the idiomatic form:

# Before
try:
    flask.send_from_directory('static', 'bad\x00')
    assert False
except BadRequest:
    pass

# After
with pytest.raises(BadRequest):
    flask.send_from_directory('static', 'bad\x00')

Applying these patterns reduces boilerplate, avoids subtle bugs (e.g. leftover patched state, unclosed files, assertions that can never run), and makes test intent clearer.