Generated unittest/xunit fixtures should be private by default (regression since 6.2.0)

[rowan-stein]

User request

Starting v6.2.0, unittest setUpClass fixtures are no longer "private"
Minimal example:

import unittest

class Tests(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        pass

    def test_1(self):
        pass

$ pytest --fixtures
...
unittest_setUpClass_fixture_Tests [class scope] -- .../site-packages/_pytest/unittest.py:145
    ... no docstring available

Expected behavior: generated fixtures should be private (prefixed with underscore) unless -v is used.

Additional context: Also affects xunit setup/teardown fixtures; likely introduced in PRs 7990, 7931, 7929. Proposed fix: prefix generated fixture names with '_'.

---

Researcher specification

Summary

• Internal autouse fixtures generated for unittest/xunit setup/teardown began appearing as public in pytest --fixtures since 6.2.0. These should be hidden by default (shown only with -v) by prefixing their names with _.

Scope and locations

• src/_pytest/unittest.py
  • Function: _make_xunit_fixture (around line ~147)
  • Current pattern: name=f"unittest_{setup_name}fixture{obj.qualname}"
  • Change to: name=f"unittest{setup_name}fixture{obj.qualname}"
• src/_pytest/python.py
  • Module._inject_setup_module_fixture (around ~531)
    • Change name to: f"xunit_setup_module_fixture{self.obj.name}"
  • Module._inject_setup_function_fixture (around ~560)
    • Change name to: f"xunit_setup_function_fixture{self.obj.name}"
  • Class._inject_setup_class_fixture (around ~812)
    • Change name to: f"xunit_setup_class_fixture{self.obj.qualname}"
  • Class._inject_setup_method_fixture (around ~841)
    • Change name to: f"xunit_setup_method_fixture{self.obj.qualname}"

Rationale

• The fixture listing code hides fixtures with a leading underscore unless -v is used. Prefixing the generated names restores expected behavior without changing functionality.

Tests to add

• New tests under testing/python/test_unittest_xunit_fixture_visibility.py to assert that:
  • Default pytest --fixtures does not show these internal fixtures.
  • pytest --fixtures -v does show them with leading underscores.
  • Similarly for --fixtures-per-test default vs -v.
  • Cover unittest setUpClass and xunit setup at module/class/method levels.

Reproduction

• Before change: create a unittest.TestCase with setUpClass and a module with setup_module; run pytest --fixtures and observe public names like unittest_setUpClass_fixture_* and xunit_setup_module_fixture_*.
• After change: those names are suppressed by default and visible with -v only.

Notes

• Behavior change likely introduced in PRs 7990/7931/7929 timeframe (pytest 6.2.0).
• No behavioral changes to test execution; only fixture display names.