"""No test file may sit where pytest will not collect it.

pytest.ini sets `testpaths = tests`, so a test file anywhere else is never run
by `pytest` and never run in CI. It still passes review, still gets maintained,
and still reports nothing.

That is not hypothetical. plugins/endpoints/tests/test_plugin.py arrived with a
merge carrying 55 lines of delivery assertions and was collected ZERO times; run
directly, five of its tests failed. A second plugin had one sitting uncollected
for longer. Both are now under tests/.

The failure mode is the worst kind: the suite is green, the coverage is imaginary,
and the authorisation on a route can be deleted without anything going red.
"""
from pathlib import Path

REPO = Path(__file__).resolve().parents[1]

# Where pytest actually looks (pytest.ini: testpaths = tests).
COLLECTED = REPO / 'tests'

# Trees that legitimately hold test-shaped files pytest must not collect:
# vendored dependencies, build output, and the frontend's own vitest specs.
IGNORED = ('node_modules', 'venv', '.git', 'dist', '__pycache__',
           'site-packages', '.plugins-staged', 'frontend')

# Whole-tree copies a build stages somewhere under the repo root. Build output,
# not source, so a test file inside one is not a stray. Empty today; add a path
# here rather than loosening IGNORED above, which matches on any path part.
IGNORED_TREES = ()


def test_every_test_file_lives_where_pytest_looks():
    stray = []
    for path in REPO.rglob('test_*.py'):
        if any(part in IGNORED for part in path.parts):
            continue
        relative = path.relative_to(REPO).as_posix()
        if any(relative.startswith(tree) for tree in IGNORED_TREES):
            continue
        if COLLECTED in path.parents:
            continue
        stray.append(path.relative_to(REPO))

    assert not stray, (
        'These test files are never collected, because pytest.ini limits\n'
        'collection to tests/. They pass review and report nothing:\n  '
        + '\n  '.join(str(p) for p in sorted(stray))
        + '\n\nMove them under tests/ (tests/test_plugins/ for plugin tests).'
    )