Fix complex negative factor filters not working (#2757)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Resolves #2747

Author: gaborbernat

docs/changelog/2634.bugfix.rst

@@ -0,0 +1,2 @@
+Fix tox auto-provisioning not working and relax :ref:`min_version` default from ``4.0`` to no version constraint
+- by user:`gaborbernat`.

docs/changelog/2720.bugfix.rst

@@ -1,2 +1,2 @@
-Fix assertion in ``test_result_json_sequential`` when interpreter
-``_base_executable`` is a hardlink (macOS homebrew) - by user:`masenf`
+Fix assertion in ``test_result_json_sequential`` when interpreter ``_base_executable`` is a hardlink (macOS homebrew)
+- by user:`masenf`.

docs/changelog/2747.bugfix.rst

@@ -0,0 +1 @@
+Complex negative factor filters not working  - by user:`gaborbernat`.

src/tox/config/loader/ini/factor.py

@@ -67,6 +67,9 @@ def find_factor_groups(value: str) -> Iterator[list[tuple[str, bool]]]:
         yield result
 
 
+_FACTOR_RE = re.compile(r"!?[\w._][\w._-]*")
+
+
 def expand_env_with_negation(value: str) -> Iterator[str]:
     """transform '{py,!pi}-{a,b},c' to ['py-a', 'py-b', '!pi-a', '!pi-b', 'c']"""
     for key, group in groupby(re.split(r"((?:{[^}]+})+)|,", value), key=bool):
@@ -76,7 +79,7 @@ def expand_env_with_negation(value: str) -> Iterator[str]:
             parts = [[i.strip() for i in elem.split(",")] for elem in elements]
             for variant in product(*parts):
                 variant_str = "".join(variant)
-                if not re.fullmatch(r"!?[\w._][\w._-]*", variant_str):
+                if not all(_FACTOR_RE.fullmatch(i) for i in variant_str.split("-")):
                     raise ValueError(variant_str)
                 yield variant_str
 

tests/config/loader/ini/test_factor.py

@@ -122,6 +122,8 @@ def test_factor_config(tox_ini_conf: ToxIniCreator) -> None:
             django15: Django>=1.5,<1.6
             django16: Django>=1.6,<1.7
             py36: unittest2
+            !py37,!django16: negation-or
+            !py37-!django16: negation-and
         """,
     )
     assert list(config) == ["py36-django15", "py36-django16", "py37-django15", "py37-django16"]
@@ -132,10 +134,14 @@ def test_factor_config(tox_ini_conf: ToxIniCreator) -> None:
         assert "pytest" in deps
         if "py36" in env:
             assert "unittest2" in deps
+            assert "negation-or" in deps
         if "django15" in env:
             assert "Django>=1.5,<1.6" in deps
+            assert "negation-or" in deps
         if "django16" in env:
             assert "Django>=1.6,<1.7" in deps
+        if "py36-django15" == env_config.name:
+            assert "negation-and" in deps
 
 
 def test_factor_config_do_not_replace_unescaped_comma(tox_ini_conf: ToxIniCreator) -> None: