Add support for virtualenv configuration options (#1862)

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

7 files changed, 81 insertions, 28 deletions

diff --git a/src/tox/config/cli/parser.py b/src/tox/config/cli/parser.py
index b1804793..f47029ba 100644
--- a/src/tox/config/cli/parser.py
+++ b/src/tox/config/cli/parser.py
@@ -87,7 +87,7 @@ class HelpFormatter(ArgumentDefaultsHelpFormatter):
         text: str = super()._get_help_string(action) or ""  # noqa
         if hasattr(action, "default_source"):
             default = " (default: %(default)s)"
-            if text.endswith(default):
+            if text.endswith(default):  # pragma: no branch
                 text = f"{text[: -len(default)]} (default: %(default)s -> from %(default_source)s)"
         return text
 
diff --git a/src/tox/execute/local_sub_process/read_via_thread_windows.py b/src/tox/execute/local_sub_process/read_via_thread_windows.py
index 9bec8962..1f4d29a1 100644
--- a/src/tox/execute/local_sub_process/read_via_thread_windows.py
+++ b/src/tox/execute/local_sub_process/read_via_thread_windows.py
@@ -15,7 +15,7 @@ class ReadViaThreadWindows(ReadViaThread):  # pragma: win32 cover
     def __init__(self, file_no: int, handler: Callable[[bytes], None], name: str, drain: bool) -> None:
         super().__init__(file_no, handler, name, drain)
         self.closed = False
-        self._ov: Optional[_overlapped.Overlapped] = None  # type: ignore[no-any-unimported]
+        self._ov: Optional[_overlapped.Overlapped] = None
         self._waiting_for_read = False
 
     def _read_stream(self) -> None:
diff --git a/src/tox/plugin/manager.py b/src/tox/plugin/manager.py
index ee3e42f8..55edb57c 100644
--- a/src/tox/plugin/manager.py
+++ b/src/tox/plugin/manager.py
@@ -21,7 +21,7 @@ from . import NAME, spec
 
 class Plugin:
     def __init__(self) -> None:
-        self.manager: pluggy.PluginManager = pluggy.PluginManager(NAME)  # type: ignore[no-any-unimported]
+        self.manager: pluggy.PluginManager = pluggy.PluginManager(NAME)
         self.manager.add_hookspecs(spec)
 
         internal_plugins = (
diff --git a/src/tox/tox_env/api.py b/src/tox/tox_env/api.py
index fe8888a5..1bff9fec 100644
--- a/src/tox/tox_env/api.py
+++ b/src/tox/tox_env/api.py
@@ -210,10 +210,26 @@ class ToxEnv(ABC):
         set_env: SetEnv = self.conf["set_env"]
         for key in set_env:
             result[key] = set_env.load(key)
-        result["PATH"] = os.pathsep.join([str(i) for i in self._paths] + os.environ.get("PATH", "").split(os.pathsep))
+        result["PATH"] = self.paths_env()
         self._env_vars = result
         return result
 
+    @property
+    def paths(self) -> List[Path]:
+        return self._paths
+
+    @paths.setter
+    def paths(self, value: List[Path]) -> None:
+        self._paths = value
+        if self._env_vars is not None:  # pragma: no branch # also update the environment variables with the new value
+            self._env_vars["PATH"] = self.paths_env()
+
+    def paths_env(self) -> str:
+        # remove duplicates and prepend the tox env paths
+        values = dict.fromkeys(str(i) for i in self.paths)
+        values.update(dict.fromkeys(os.environ.get("PATH", "").split(os.pathsep)))
+        return os.pathsep.join(values)
+
     def execute(
         self,
         cmd: Sequence[Union[Path, str]],
diff --git a/src/tox/tox_env/python/api.py b/src/tox/tox_env/python/api.py
index f2950dd7..cc2ffd68 100644
--- a/src/tox/tox_env/python/api.py
+++ b/src/tox/tox_env/python/api.py
@@ -158,9 +158,13 @@ class Python(ToxEnv, ABC):
         with self._cache.compare(conf, Python.__name__) as (eq, old):
             if eq is False:  # if changed create
                 self.create_python_env()
-            self._paths = self.paths()
+        self.paths = self.python_env_paths()  # now that the environment exist we can add them to the path
         super().setup()
 
+    @abstractmethod
+    def python_env_paths(self) -> List[Path]:
+        raise NotImplementedError
+
     def setup_has_been_done(self) -> None:
         """called when setup is done"""
         super().setup_has_been_done()
@@ -228,10 +232,6 @@ class Python(ToxEnv, ABC):
         raise NotImplementedError
 
     @abstractmethod
-    def paths(self) -> List[Path]:
-        raise NotImplementedError
-
-    @abstractmethod
     def install_python_packages(self, packages: PythonDeps, of_type: str, no_deps: bool = False) -> None:
         raise NotImplementedError
 
diff --git a/src/tox/tox_env/python/virtual_env/api.py b/src/tox/tox_env/python/virtual_env/api.py
index 5af0a504..fb28a5b7 100644
--- a/src/tox/tox_env/python/virtual_env/api.py
+++ b/src/tox/tox_env/python/virtual_env/api.py
@@ -10,6 +10,7 @@ from virtualenv.create.creator import Creator
 from virtualenv.run.session import Session
 
 from tox.config.cli.parser import DEFAULT_VERBOSITY, Parsed
+from tox.config.loader.str_convert import StrConvert
 from tox.config.sets import CoreConfigSet, EnvConfigSet
 from tox.execute.api import Execute, Outcome, StdinSource
 from tox.execute.local_sub_process import LocalSubProcessExecutor
@@ -25,9 +26,38 @@ class VirtualEnv(Python, ABC):
     def __init__(
         self, conf: EnvConfigSet, core: CoreConfigSet, options: Parsed, journal: EnvJournal, log_handler: ToxHandler
     ) -> None:
-        self._virtualenv_session: Optional[Session] = None  # type: ignore[no-any-unimported]
+        self._virtualenv_session: Optional[Session] = None
         super().__init__(conf, core, options, journal, log_handler)
 
+    def register_config(self) -> None:
+        super().register_config()
+        self.conf.add_config(
+            keys=["system_site_packages", "sitepackages"],
+            of_type=bool,
+            default=lambda conf, name: StrConvert().to_bool(
+                self.environment_variables.get("VIRTUALENV_SYSTEM_SITE_PACKAGES", "False")
+            ),
+            desc="create virtual environments that also have access to globally installed packages.",
+        )
+        self.conf.add_config(
+            keys=["always_copy", "alwayscopy"],
+            of_type=bool,
+            default=lambda conf, name: StrConvert().to_bool(
+                self.environment_variables.get(
+                    "VIRTUALENV_COPIES", self.environment_variables.get("VIRTUALENV_ALWAYS_COPY", "False")
+                )
+            ),
+            desc="force virtualenv to always copy rather than symlink",
+        )
+        self.conf.add_config(
+            keys=["download"],
+            of_type=bool,
+            default=lambda conf, name: StrConvert().to_bool(
+                self.environment_variables.get("VIRTUALENV_DOWNLOAD", "False")
+            ),
+            desc="true if you want virtualenv to upgrade pip/wheel/setuptools to the latest version",
+        )
+
     def default_pass_env(self) -> List[str]:
         env = super().default_pass_env()
         env.append("PIP_*")  # we use pip as installer
@@ -37,28 +67,37 @@ class VirtualEnv(Python, ABC):
     def default_set_env(self) -> Dict[str, str]:
         env = super().default_set_env()
         env["PIP_DISABLE_PIP_VERSION_CHECK"] = "1"
-        env["VIRTUALENV_NO_PERIODIC_UPDATE"] = "1"
         return env
 
     def build_executor(self) -> Execute:
         return LocalSubProcessExecutor(self.options.is_colored)
 
     @property
-    def session(self) -> Session:  # type: ignore[no-any-unimported]
+    def session(self) -> Session:
         if self._virtualenv_session is None:
-            args = [
-                "--clear",
-                "--no-periodic-update",
-                str(cast(Path, self.conf["env_dir"])),
-            ]
-            base_python: List[str] = self.conf["base_python"]
-            for base in base_python:
-                args.extend(["-p", base])
-            self._virtualenv_session = session_via_cli(args, setup_logging=False)
+            self._virtualenv_session = session_via_cli(
+                [str(cast(Path, self.conf["env_dir"]))],
+                options=None,
+                setup_logging=False,
+                env=self.virtualenv_env_vars(),
+            )
         return self._virtualenv_session
 
+    def virtualenv_env_vars(self) -> Dict[str, str]:
+        env = self.environment_variables.copy()
+        base_python: List[str] = self.conf["base_python"]
+        if "VIRTUALENV_CLEAR" not in env:
+            env["VIRTUALENV_CLEAR"] = "True"
+        if "VIRTUALENV_NO_PERIODIC_UPDATE" not in env:
+            env["VIRTUALENV_NO_PERIODIC_UPDATE"] = "True"
+        env["VIRTUALENV_SYSTEM_SITE_PACKAGES"] = str(self.conf["system_site_packages"])
+        env["VIRTUALENV_COPIES"] = str(self.conf["always_copy"])
+        env["VIRTUALENV_DOWNLOAD"] = str(self.conf["download"])
+        env["VIRTUALENV_PYTHON"] = "\n".join(base_python)
+        return env
+
     @property
-    def creator(self) -> Creator:  # type: ignore[no-any-unimported]
+    def creator(self) -> Creator:
         return self.session.creator
 
     def create_python_env(self) -> None:
@@ -79,10 +118,10 @@ class VirtualEnv(Python, ABC):
             extra_version_info=None,
         )
 
-    def paths(self) -> List[Path]:
+    def python_env_paths(self) -> List[Path]:
         """Paths to add to the executable"""
         # we use the original executable as shims may be somewhere else
-        return list({self.creator.bin_dir, self.creator.script_dir})
+        return list(dict.fromkeys((self.creator.bin_dir, self.creator.script_dir)))
 
     def env_site_package_dir(self) -> Path:
         return cast(Path, self.creator.purelib)
diff --git a/src/tox/tox_env/python/virtual_env/package/api.py b/src/tox/tox_env/python/virtual_env/package/api.py
index 8bf28c5b..b3a0a11b 100644
--- a/src/tox/tox_env/python/virtual_env/package/api.py
+++ b/src/tox/tox_env/python/virtual_env/package/api.py
@@ -90,7 +90,7 @@ class Pep517VirtualEnvPackage(VirtualEnv, PythonPackage, Frontend):
     ) -> None:
         VirtualEnv.__init__(self, conf, core, options, journal, log_handler)
         Frontend.__init__(self, *Frontend.create_args_from_folder(core["tox_root"]))
-        self._distribution_meta: Optional[PathDistribution] = None  # type: ignore[no-any-unimported]
+        self._distribution_meta: Optional[PathDistribution] = None
         self._build_requires: Optional[Tuple[Requirement]] = None
         self._build_wheel_cache: Optional[WheelResult] = None
         self._backend_executor: Optional[LocalSubProcessPep517Executor] = None
@@ -217,9 +217,7 @@ class Pep517VirtualEnvPackage(VirtualEnv, PythonPackage, Frontend):
         return self._package_dependencies
 
     @staticmethod
-    def discover_package_dependencies(  # type: ignore[no-any-unimported]
-        meta: PathDistribution, extras: Set[str]
-    ) -> List[Requirement]:
+    def discover_package_dependencies(meta: PathDistribution, extras: Set[str]) -> List[Requirement]:
         result: List[Requirement] = []
         requires = meta.requires or []
         for req_str in requires: