Fix change_dir is not always relative to tox_root (#2761)

Resolves #2619

Author: gaborbernat

.pre-commit-config.yaml

@@ -58,7 +58,7 @@ repos:
           - flake8-spellcheck==0.28
           - flake8-unused-arguments==0.0.12
           - flake8-noqa==1.3
-          - pep8-naming==0.13.2
+          - pep8-naming==0.13.3
           - flake8-pyproject==1.2.2
   - repo: https://github.com/pre-commit/mirrors-prettier
     rev: "v2.7.1"

docs/changelog/2619.bugfix.rst

@@ -0,0 +1,2 @@
+Fix :ref:`change_dir` is relative to current working directory rather than to the :ref:`tox_root` when using the ``-c``
+argument to locate the ``tox.ini`` file - by :user:`gaborbernat`.

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
 build-backend = "hatchling.build"
-requires = ["hatchling>=1.11.1", "hatch-vcs>=0.2.1"]
+requires = ["hatchling>=1.11.1", "hatch-vcs>=0.3"]
 
 [project]
 name = "tox"
@@ -31,7 +31,7 @@ dependencies = [
   'tomli>=2.0.1; python_version < "3.11"',
   "virtualenv>=20.17.1",
   "filelock>=3.8.2",
-  'importlib-metadata>=5.1; python_version < "3.8"',
+  'importlib-metadata>=5.2; python_version < "3.8"',
   'typing-extensions>=4.4; python_version < "3.8"',
 ]
 optional-dependencies.docs = [
@@ -51,7 +51,7 @@ optional-dependencies.testing = [
   "diff-cover>=7.3",
   "distlib>=0.3.6",
   "flaky>=3.7",
-  "hatch-vcs>=0.2.1",
+  "hatch-vcs>=0.3",
   "hatchling>=1.11.1",
   "psutil>=5.9.4",
   "pytest>=7.2",

src/tox/tox_env/python/virtual_env/package/cmd_builder.py

@@ -26,6 +26,7 @@
 from tox.tox_env.python.virtual_env.api import VirtualEnv
 from tox.tox_env.register import ToxEnvRegister
 from tox.tox_env.runner import RunToxEnv
+from tox.tox_env.util import add_change_dir_conf
 
 from .pyproject import Pep517VirtualEnvPackager
 from .util import dependencies_with_extras
@@ -61,12 +62,7 @@ def register_config(self) -> None:
             default=[],
             desc="the commands to be called for testing",
         )
-        self.conf.add_config(
-            keys=["change_dir", "changedir"],
-            of_type=Path,
-            default=lambda conf, name: cast(Path, conf.core["tox_root"]),  # noqa: U100
-            desc="change to this working directory when executing the test command",
-        )
+        add_change_dir_conf(self.conf, self.core)
         self.conf.add_config(
             keys=["ignore_errors"],
             of_type=bool,

src/tox/tox_env/runner.py

@@ -5,14 +5,14 @@
 import re
 from abc import ABC, abstractmethod
 from hashlib import sha256
-from pathlib import Path
-from typing import Any, Iterable, List, cast
+from typing import Any, Iterable, List
 
 from tox.config.types import Command, EnvList
 from tox.journal import EnvJournal
 
 from .api import ToxEnv, ToxEnvCreateArgs
 from .package import Package, PackageToxEnv, PathPackage
+from .util import add_change_dir_conf
 
 
 class RunToxEnv(ToxEnv, ABC):
@@ -58,12 +58,7 @@ def ensure_one_line(value: str) -> str:
             default=[],
             desc="the commands to be called after testing",
         )
-        self.conf.add_config(
-            keys=["change_dir", "changedir"],
-            of_type=Path,
-            default=lambda conf, name: cast(Path, conf.core["tox_root"]),  # noqa: U100
-            desc="change to this working directory when executing the test command",
-        )
+        add_change_dir_conf(self.conf, self.core)
         self.conf.add_config(
             keys=["args_are_paths"],
             of_type=bool,

src/tox/tox_env/util.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import cast
+
+from tox.config.sets import CoreConfigSet, EnvConfigSet
+
+
+def add_change_dir_conf(config: EnvConfigSet, core: CoreConfigSet) -> None:
+    def _post_process_change_dir(value: Path) -> Path:
+        if not value.is_absolute():
+            value = (core["tox_root"] / value).resolve()
+        return value
+
+    config.add_config(
+        keys=["change_dir", "changedir"],
+        of_type=Path,
+        default=lambda conf, name: cast(Path, conf.core["tox_root"]),  # noqa: U100
+        desc="change to this working directory when executing the test command",
+        post_process=_post_process_change_dir,
+    )
+
+
+__all__ = [
+    "add_change_dir_conf",
+]

tests/tox_env/test_tox_env_api.py

@@ -113,3 +113,11 @@ def test_change_dir_is_created_if_not_exist(tox_project: ToxProjectCreator) -> N
     result_first = prj.run("r")
     result_first.assert_success()
     assert (prj.path / "a" / "b").exists()
+
+
+def test_change_dir_is_relative_to_conf(tox_project: ToxProjectCreator) -> None:
+    prj = tox_project({"tox.ini": "[testenv]\npackage=skip\nchange_dir=a"})
+    result = prj.run("c", "-e", "py", "-k", "change_dir", "-c", prj.path.name, from_cwd=prj.path.parent)
+    result.assert_success()
+    lines = result.out.splitlines()
+    assert lines[1] == f"change_dir = {prj.path / 'a'}"