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

Resolves https://github.com/tox-dev/tox/issues/2619

3 files changed, 31 insertions, 14 deletions

diff --git a/src/tox/tox_env/python/virtual_env/package/cmd_builder.py b/src/tox/tox_env/python/virtual_env/package/cmd_builder.py
index 9140a936..2d6097a4 100644
--- a/src/tox/tox_env/python/virtual_env/package/cmd_builder.py
+++ b/src/tox/tox_env/python/virtual_env/package/cmd_builder.py
@@ -26,6 +26,7 @@ from tox.tox_env.python.pip.req_file import PythonDeps
 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 @@ class VirtualEnvCmdBuilder(PythonPackageToxEnv, VirtualEnv):
             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,
diff --git a/src/tox/tox_env/runner.py b/src/tox/tox_env/runner.py
index c9c3c6ad..fb9a95e0 100644
--- a/src/tox/tox_env/runner.py
+++ b/src/tox/tox_env/runner.py
@@ -5,14 +5,14 @@ import os
 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 @@ class RunToxEnv(ToxEnv, ABC):
             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,
diff --git a/src/tox/tox_env/util.py b/src/tox/tox_env/util.py
new file mode 100644
index 00000000..aa13f12b
--- /dev/null
+++ b/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",
+]