ruff-tests.toml

# Lint config for the test tree, which ruff.toml excludes from `ruff check`.
#
# Every rule here catches a test that cannot fail. Rules land one at a time, each
# with its existing violations already fixed, so this list never needs a budget
# file or a ratchet.
#
# F821    a name that does not exist raises NameError, and a test body wrapped in
#         `except Exception: pass` swallows that NameError and reports green
# B011    `assert False` inside `try:` raises AssertionError, which the `except
#         Exception` below it catches. `pytest.fail` raises BaseException and escapes
# PT015   same site as B011, from the pytest ruleset
# B015    a bare `a == b` statement is evaluated and thrown away; the missing `assert`
#         means the test checks nothing
# B018    a bare attribute access or literal, usually a call missing its parens
# PLW0127 `x = x` self-assignment, dead code that reads like a narrowing or a fixup
# PLR0133 comparison of two constants, e.g. `assert True == True`
# B017    `pytest.raises(Exception)` accepts the TypeError a refactor introduced just as
#         readily as the rejection under test, so a crash reads as a pass. Narrow to the
#         real type, or add `match=` where the code genuinely raises a bare Exception
# PT012   a `pytest.raises` block that runs on past the raising call. Everything after
#         that call is dead, so an `assert` sitting there is never checked. Keep the
#         block to the call itself and put the assertions below it
# PT011   `pytest.raises(Exception)` / `(ValueError)` / `(OSError)` with no `match=`. The
#         block passes on any error that broad, so the TypeError a refactor introduced
#         reads as the rejection under test. Pin the message the code actually raises
# PT014   the same `parametrize` case listed twice. The copy re-runs an assertion that
#         already passed and adds no coverage, and it usually marks a case someone meant
#         to vary and forgot to edit
#
# No target-version here on purpose: it resolves from requires-python (>=3.10), so
# 3.11-only builtins like BaseExceptionGroup are correctly flagged in a tree that
# still has to run on 3.10.

line-length = 120

lint.select = ["F821", "B011", "B015", "B017", "B018", "PT011", "PT012", "PT014", "PT015", "PLR0133", "PLW0127"]