Add support for virtualenv configuration options (#1862)

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

2 files changed, 109 insertions, 2 deletions

diff --git a/tests/tox_env/python/virtual_env/test_package.py b/tests/tox_env/python/virtual_env/test_package.py
index 378a6fb7..9ba1f14e 100644
--- a/tests/tox_env/python/virtual_env/test_package.py
+++ b/tests/tox_env/python/virtual_env/test_package.py
@@ -23,9 +23,9 @@ def test_tox_ini_package_type_valid(tox_project: ToxProjectCreator, pkg_type: st
     proj = tox_project({"tox.ini": f"[testenv]\npackage={pkg_type}"})
     result = proj.run("c", "-k", "package_tox_env_type")
     result.assert_success()
-    res = result.state.tox_env("py").conf["package"]
+    res = result.env_conf("py")["package"]
     assert res is getattr(PackageType, pkg_type)
-    got_type = result.state.tox_env("py").conf["package_tox_env_type"]
+    got_type = result.env_conf("py")["package_tox_env_type"]
     assert got_type == "virtualenv-pep-517"
 
 
diff --git a/tests/tox_env/python/virtual_env/test_virtualenv_api.py b/tests/tox_env/python/virtual_env/test_virtualenv_api.py
new file mode 100644
index 00000000..8320b9dc
--- /dev/null
+++ b/tests/tox_env/python/virtual_env/test_virtualenv_api.py
@@ -0,0 +1,107 @@
+import os
+
+import pytest
+from pytest_mock import MockerFixture
+from virtualenv import session_via_cli
+from virtualenv.config.cli.parser import VirtualEnvOptions
+
+from tox.pytest import MonkeyPatch, ToxProject, ToxProjectCreator
+
+
+@pytest.fixture()
+def virtualenv_opt(monkeypatch: MonkeyPatch, mocker: MockerFixture) -> VirtualEnvOptions:
+    for key in os.environ:
+        if key.startswith("VIRTUALENV_"):  # pragma: no cover
+            monkeypatch.delenv(key)  # pragma: no cover
+    opts = VirtualEnvOptions()
+    mocker.patch(
+        "tox.tox_env.python.virtual_env.api.session_via_cli",
+        side_effect=lambda args, options, setup_logging, env: session_via_cli(args, opts, setup_logging, env),
+    )
+    return opts
+
+
+def test_virtualenv_default_settings(tox_project: ToxProjectCreator, virtualenv_opt: VirtualEnvOptions) -> None:
+    proj = tox_project({"tox.ini": "[testenv]\npackage=skip"})
+    result = proj.run("r", "-e", "py")
+    result.assert_success()
+
+    conf = result.env_conf("py")
+    assert conf["system_site_packages"] is False
+    assert conf["always_copy"] is False
+    assert conf["download"] is False
+
+    assert virtualenv_opt.clear is True
+    assert virtualenv_opt.system_site is False
+    assert virtualenv_opt.download is False
+    assert virtualenv_opt.copies is False
+    assert virtualenv_opt.no_periodic_update is True
+    assert virtualenv_opt.python == ["py"]
+
+
+def test_virtualenv_flipped_settings(
+    tox_project: ToxProjectCreator, virtualenv_opt: VirtualEnvOptions, monkeypatch: MonkeyPatch
+) -> None:
+    proj = tox_project(
+        {"tox.ini": "[testenv]\npackage=skip\nsystem_site_packages=True\nalways_copy=True\ndownload=True"}
+    )
+    monkeypatch.setenv("VIRTUALENV_CLEAR", "0")
+
+    result = proj.run("r", "-e", "py")
+    result.assert_success()
+
+    conf = result.env_conf("py")
+    assert conf["system_site_packages"] is True
+    assert conf["always_copy"] is True
+    assert conf["download"] is True
+
+    assert virtualenv_opt.clear is False
+    assert virtualenv_opt.system_site is True
+    assert virtualenv_opt.download is True
+    assert virtualenv_opt.copies is True
+    assert virtualenv_opt.python == ["py"]
+
+
+def test_virtualenv_env_ignored_if_set(
+    tox_project: ToxProjectCreator, virtualenv_opt: VirtualEnvOptions, monkeypatch: MonkeyPatch
+) -> None:
+    ini = "[testenv]\npackage=skip\nsystem_site_packages=True\nalways_copy=True\ndownload=True"
+    proj = tox_project({"tox.ini": ini})
+    monkeypatch.setenv("VIRTUALENV_COPIES", "0")
+    monkeypatch.setenv("VIRTUALENV_DOWNLOAD", "0")
+    monkeypatch.setenv("VIRTUALENV_SYSTEM_SITE_PACKAGES", "0")
+    run_and_check_set(proj, virtualenv_opt)
+
+
+def test_virtualenv_env_used_if_not_set(
+    tox_project: ToxProjectCreator, virtualenv_opt: VirtualEnvOptions, monkeypatch: MonkeyPatch
+) -> None:
+    proj = tox_project({"tox.ini": "[testenv]\npackage=skip"})
+    monkeypatch.setenv("VIRTUALENV_COPIES", "1")
+    monkeypatch.setenv("VIRTUALENV_DOWNLOAD", "1")
+    monkeypatch.setenv("VIRTUALENV_SYSTEM_SITE_PACKAGES", "1")
+    run_and_check_set(proj, virtualenv_opt)
+
+
+def run_and_check_set(proj: ToxProject, virtualenv_opt: VirtualEnvOptions) -> None:
+    result = proj.run("r", "-e", "py")
+    result.assert_success()
+    conf = result.env_conf("py")
+    assert conf["system_site_packages"] is True
+    assert conf["always_copy"] is True
+    assert conf["download"] is True
+    assert virtualenv_opt.system_site is True
+    assert virtualenv_opt.download is True
+    assert virtualenv_opt.copies is True
+
+
+def test_honor_set_env_for_clear_periodic_update(
+    tox_project: ToxProjectCreator, virtualenv_opt: VirtualEnvOptions, monkeypatch: MonkeyPatch
+) -> None:
+    ini = "[testenv]\npackage=skip\nset_env=\n  VIRTUALENV_CLEAR=0\n  VIRTUALENV_NO_PERIODIC_UPDATE=0"
+    proj = tox_project({"tox.ini": ini})
+    result = proj.run("r", "-e", "py")
+    result.assert_success()
+
+    assert virtualenv_opt.clear is False
+    assert virtualenv_opt.no_periodic_update is False