python config_error ai_generated true

ScopeMismatch: You tried to access the function scoped fixture 'tmp_path' with a session scoped request object

ID: python/pytest-scope-mismatch-session-in-function

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-04-08First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
7.x active — — —
8.x active — — —

Root Cause

A session/module-scoped fixture depends on a narrower-scoped fixture. pytest forbids a wider scope from consuming a narrower one because the narrower fixture would be torn down before the wider one.

generic

中文

session/module 作用域的 fixture 依赖了更窄作用域的 fixture。pytest 禁止宽作用域消费窄作用域，因为窄 fixture 会在宽 fixture 之前被拆除。

Workarounds

  1. 93% success 
    @pytest.fixture(scope='session')
def tmp_root(tmp_path_factory):
    return tmp_path_factory.mktemp('root')

@pytest.fixture(scope='session')
def settings(tmp_root):
    return load(tmp_root)
  2. 90% success 
    @pytest.fixture(scope='session')
def db(tmp_path_factory):
    path = tmp_path_factory.mktemp('db')
    return init_db(path)

Dead Ends

Common approaches that don't work:

  1. 80% fail

    autouse doesn't change scope; the mismatch remains and pytest still raises ScopeMismatch.

  2. 85% fail

    The lambda still references the same fixture object; pytest resolves dependencies before invocation.