def test_show_fixtures_different_files(self, pytester: Pytester) -> None:
        """`--fixtures` only shows fixtures from first file (#833)."""
        pytester.makepyfile(
            test_a='''
            import pytest

            @pytest.fixture
            def fix_a():
                """Fixture A"""
                pass

            def test_a(fix_a):
                pass
        '''
        )
        pytester.makepyfile(
            test_b='''
            import pytest

            @pytest.fixture
            def fix_b():
                """Fixture B"""
                pass

            def test_b(fix_b):
                pass
        '''
        )
        result = pytester.runpytest("--fixtures")
        result.stdout.fnmatch_lines(
            """
            * fixtures defined from test_a *
            fix_a -- test_a.py:4
                Fixture A

            * fixtures defined from test_b *
            fix_b -- test_b.py:4
                Fixture B
        """
        )
`--fixtures` only shows fixtures from first file (#833).
testing/python/fixtures.py