Add on platform constat to core

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

docs/changelog/3315.feature.rst

@@ -0,0 +1,2 @@
+Add :ref:`on_platform` core configuration holding the tox platform and do not install package when exec an environment
+- by :user:`gaborbernat`.

docs/config.rst

@@ -215,6 +215,12 @@ The following options are set in the ``[tox]`` section of ``tox.ini`` or the ``[
            test = py310, py39
            static = flake8, mypy
 
+.. conf::
+   :keys: on_platform
+   :constant:
+
+   A constant holding the platform of the tox runtime environment.
+
 Python language core options
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

pyproject.toml

@@ -50,7 +50,7 @@ dynamic = [
   "version",
 ]
 dependencies = [
-  "cachetools>=5.3.3",
+  "cachetools>=5.4",
   "chardet>=5.2",
   "colorama>=0.4.6",
   "filelock>=3.15.4",
@@ -62,10 +62,10 @@ dependencies = [
   "virtualenv>=20.26.3",
 ]
 optional-dependencies.docs = [
-  "furo>=2024.5.6",
-  "sphinx>=7.3.7",
+  "furo>=2024.7.18",
+  "sphinx>=7.4.7",
   "sphinx-argparse-cli>=1.16",
-  "sphinx-autodoc-typehints!=1.23.4,>=2.2.2",
+  "sphinx-autodoc-typehints>=2.2.3",
   "sphinx-copybutton>=0.5.2",
   "sphinx-inline-tabs>=2023.4.21",
   "sphinxcontrib-towncrier>=0.2.1a0",
@@ -76,18 +76,18 @@ optional-dependencies.testing = [
   "covdefaults>=2.3",
   "detect-test-pollution>=1.2",
   "devpi-process>=1",
-  "diff-cover>=9.1",
+  "diff-cover>=9.1.1",
   "distlib>=0.3.8",
   "flaky>=3.8.1",
   "hatch-vcs>=0.4",
   "hatchling>=1.25",
   "psutil>=6",
-  "pytest>=8.2.2",
+  "pytest>=8.3.2",
   "pytest-cov>=5",
   "pytest-mock>=3.14",
   "pytest-xdist>=3.6.1",
   "re-assert>=1.1",
-  "setuptools>=70.2",
+  "setuptools>=70.3",
   "time-machine>=2.14.2; implementation_name!='pypy'",
   "wheel>=0.43",
 ]

src/tox/session/cmd/exec_.py

@@ -28,6 +28,7 @@ def tox_add_option(parser: ToxParser) -> None:
 
 
 def exec_(state: State) -> int:
+    state.conf.options.skip_pkg_install = True  # avoid package install
     envs = list(state.envs.iter())
     if len(envs) != 1:
         msg = f"exactly one target environment allowed in exec mode but found {', '.join(envs)}"

src/tox/session/state.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import sys
 from typing import TYPE_CHECKING, Sequence
 
 from tox.config.main import Config
@@ -18,6 +19,11 @@ class State:
 
     def __init__(self, options: Options, args: Sequence[str]) -> None:
         self.conf = Config.make(options.parsed, options.pos_args, options.source)
+        self.conf.core.add_constant(
+            keys=["on_platform"],
+            desc="platform we are running on",
+            value=sys.platform,
+        )
         self._options = options
         self.args = args
         self._journal: Journal = Journal(getattr(options.parsed, "result_json", None) is not None)

tests/session/cmd/test_show_config.py

@@ -283,3 +283,10 @@ def test_package_env_inherits_from_pkgenv(tox_project: ToxProjectCreator, demo_p
     """
     exp = dedent(exp)
     assert exp in outcome.out
+
+
+def test_core_on_platform(tox_project: ToxProjectCreator) -> None:
+    project = tox_project({"tox.ini": "[tox]\nno_package = true"})
+    result = project.run("c", "-e", "py", "--core", "-k", "on_platform")
+    result.assert_success()
+    assert result.out == f"[testenv:py]\n\n[tox]\non_platform = {sys.platform}\n"

tox.ini

@@ -40,7 +40,7 @@ commands =
 description = format the code base to adhere to our styles, and complain about what we cannot do automatically
 skip_install = true
 deps =
-    pre-commit>=3.7.1
+    pre-commit>=3.8
 pass_env =
     {[testenv]passenv}
     PROGRAMDATA
@@ -51,8 +51,8 @@ commands =
 [testenv:type]
 description = run type check on code base
 deps =
-    mypy==1.10.1
-    types-cachetools>=5.3.0.7
+    mypy==1.11
+    types-cachetools>=5.4.0.20240717
     types-chardet>=5.0.4.6
 commands =
     mypy src/tox