Allow disabling plugins on a one-off

Signed-off-by: Bernát Gábor <[email protected]>

Author: gaborbernat

docs/changelog/3468.feature.rst

@@ -0,0 +1 @@
+Allow disabling tox plugins via the ``TOX_DISABLED_EXTERNAL_PLUGINS`` environment variable - by :user:`gaborbernat`.

docs/plugins.rst

@@ -27,6 +27,13 @@ installed. For example:
 
 For more information, refer to :ref:`the user guide <auto-provisioning>`.
 
+Plugins can be disabled via the ``TOX_DISABLED_EXTERNAL_PLUGINS`` environment variable. This variable can be set to a
+comma separated list of plugin names, e.g.:
+
+```bash
+env TOX_DISABLED_EXTERNAL_PLUGINS=tox-uv,tox-extra tox --version
+```
+
 Developing your own plugin
 --------------------------
 

pyproject.toml

@@ -62,11 +62,6 @@ dependencies = [
   "typing-extensions>=4.12.2; python_version<'3.11'",
   "virtualenv>=20.31",
 ]
-optional-dependencies.test = [
-  "devpi-process>=1.0.2",
-  "pytest>=8.3.4",
-  "pytest-mock>=3.14",
-]
 urls.Documentation = "https://tox.wiki"
 urls.Homepage = "http://tox.readthedocs.org"
 urls."Release Notes" = "https://tox.wiki/en/latest/changelog.html"

src/tox/plugin/manager.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import os
 from typing import TYPE_CHECKING, Any
 
 import pluggy
@@ -49,7 +50,7 @@ def _register_plugins(self, inline: ModuleType | None) -> None:
 
         if inline is not None:
             self.manager.register(inline)
-        self.manager.load_setuptools_entrypoints(NAME)
+        self._load_external_plugins()
         internal_plugins = (
             loader_api,
             provision,
@@ -74,6 +75,11 @@ def _register_plugins(self, inline: ModuleType | None) -> None:
         self.manager.register(state)
         self.manager.check_pending()
 
+    def _load_external_plugins(self) -> None:
+        for name in os.environ.get("TOX_DISABLED_EXTERNAL_PLUGINS", "").split(","):
+            self.manager.set_blocked(name)
+        self.manager.load_setuptools_entrypoints(NAME)
+
     def tox_add_option(self, parser: ToxParser) -> None:
         self.manager.hook.tox_add_option(parser=parser)
 

src/tox/pytest.py

@@ -82,7 +82,10 @@ def _load_inline(path: Path) -> ModuleType | None:  # register only on first run
 @contextmanager
 def check_os_environ() -> Iterator[None]:
     old = os.environ.copy()
-    to_clean = {k: os.environ.pop(k, None) for k in (ENV_VAR_KEY, "TOX_WORK_DIR", "PYTHONPATH", "COV_CORE_CONTEXT")}
+    to_clean = {
+        k: os.environ.pop(k, None)
+        for k in (ENV_VAR_KEY, "TOX_WORK_DIR", "PYTHONPATH", "COV_CORE_CONTEXT", "TOX_DISABLED_EXTERNAL_PLUGINS")
+    }
 
     yield
 
@@ -93,6 +96,7 @@ def check_os_environ() -> Iterator[None]:
     new = os.environ
     extra = {k: new[k] for k in set(new) - set(old)}
     extra.pop("PLAT", None)
+    extra.pop("TOX_DISABLED_EXTERNAL_PLUGINS", None)
     miss = {k: old[k] for k in set(old) - set(new)}
     diff = {
         f"{k} = {old[k]} vs {new[k]}" for k in set(old) & set(new) if old[k] != new[k] and not k.startswith("PYTEST_")

tests/plugin/test_plugin.py

@@ -13,6 +13,7 @@
 from tox.config.sets import ConfigSet, CoreConfigSet, EnvConfigSet
 from tox.execute import Outcome
 from tox.plugin import impl
+from tox.plugin.manager import Plugin
 from tox.pytest import ToxProjectCreator, register_inline_plugin
 from tox.session.state import State
 from tox.tox_env.api import ToxEnv
@@ -21,6 +22,7 @@
 if TYPE_CHECKING:
     from pathlib import Path
 
+    from pluggy import PluginManager
     from pytest_mock import MockerFixture
 
 
@@ -268,3 +270,45 @@ def tox_after_run_commands(tox_env: ToxEnv, exit_code: int, outcomes: list[Outco
     project = tox_project({"tox.ini": "[testenv]\npackage=skip"})
     result = project.run("r")
     result.assert_success()
+
+
+@pytest.mark.parametrize(
+    ("env_val", "expect_a", "expect_b"),
+    [
+        pytest.param("", True, True, id="none_disabled"),
+        pytest.param("dummy_plugin_a,dummy_plugin_b", False, False, id="both_disabled"),
+        pytest.param("dummy_plugin_a", False, True, id="only_a_disabled"),
+        pytest.param("dummy_plugin_b", True, False, id="only_b_disabled"),
+    ],
+)
+def test_disable_external_plugins(
+    tox_project: ToxProjectCreator,
+    mocker: MockerFixture,
+    env_val: str,
+    expect_a: bool,
+    expect_b: bool,
+) -> None:
+    class DummyPluginA:
+        @staticmethod
+        @impl
+        def tox_add_option(parser: ToxParser) -> None:  # noqa: ARG004
+            logging.warning("dummy plugin A called")
+
+    class DummyPluginB:
+        @staticmethod
+        @impl
+        def tox_add_option(parser: ToxParser) -> None:  # noqa: ARG004
+            logging.warning("dummy plugin B called")
+
+    def fake_load_entrypoints(self: PluginManager, name: str) -> None:  # noqa: ARG001
+        self.register(DummyPluginA(), name="dummy_plugin_a")
+        self.register(DummyPluginB(), name="dummy_plugin_b")
+
+    mocker.patch("pluggy.PluginManager.load_setuptools_entrypoints", fake_load_entrypoints)
+    mocker.patch.dict(os.environ, {"TOX_DISABLED_EXTERNAL_PLUGINS": env_val})
+    mocker.patch("tox.plugin.manager.MANAGER", Plugin())
+    project = tox_project({"tox.ini": ""})
+    result = project.run("--version")
+    result.assert_success()
+    assert ("dummy plugin A called" in result.out) == expect_a
+    assert ("dummy plugin B called" in result.out) == expect_b