Selectively enable user site

The modern virtual environment structure does not allow us to enable
"fake user site" while disabling the global site, so we need to do more
fine-grained configuration to correctly set up test environments for
each test case.

With this done, we can also properly support the stdlib venv ad the test
environment backend, since it basically works identically with modern
virtualenv. The incompatible_with_test_venv is thus removed.

Author: uranusjr

setup.cfg

@@ -63,7 +63,6 @@ xfail_strict = True
 markers =
     network: tests that need network
     incompatible_with_sysconfig
-    incompatible_with_test_venv
     incompatible_with_venv
     no_auto_tempdir_manager
     unit: unit tests

tests/conftest.py

@@ -108,10 +108,6 @@ def pytest_collection_modifyitems(config: Config, items: List[pytest.Function])
             if item.get_closest_marker("network") is not None:
                 item.add_marker(pytest.mark.flaky(reruns=3, reruns_delay=2))
 
-        if item.get_closest_marker("incompatible_with_test_venv") and config.getoption(
-            "--use-venv"
-        ):
-            item.add_marker(pytest.mark.skip("Incompatible with test venv"))
         if (
             item.get_closest_marker("incompatible_with_venv")
             and sys.prefix != sys.base_prefix
@@ -474,9 +470,6 @@ def virtualenv_template(
         ):
             (venv.bin / exe).unlink()
 
-    # Enable user site packages.
-    venv.user_site_packages = True
-
     # Rename original virtualenv directory to make sure
     # it's not reused by mistake from one of the copies.
     venv_template = tmpdir / "venv_template"
@@ -742,3 +735,8 @@ def mock_server() -> Iterator[MockServer]:
 @pytest.fixture
 def proxy(request: pytest.FixtureRequest) -> str:
     return request.config.getoption("proxy")
+
+
+@pytest.fixture
+def enable_user_site(virtualenv: VirtualEnvironment) -> None:
+    virtualenv.user_site_packages = True

tests/functional/test_build_env.py

@@ -204,7 +204,7 @@ def test_build_env_overlay_prefix_has_priority(script: PipTestEnvironment) -> No
     assert result.stdout.strip() == "2.0", str(result)
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_build_env_isolation(script: PipTestEnvironment) -> None:
 
     # Create dummy `pkg` wheel.

tests/functional/test_freeze.py

@@ -862,7 +862,7 @@ def test_freeze_with_requirement_option_package_repeated_multi_file(
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_freeze_user(
     script: PipTestEnvironment, virtualenv: VirtualEnvironment, data: TestData
 ) -> None:
@@ -900,7 +900,7 @@ def test_freeze_path(tmpdir: Path, script: PipTestEnvironment, data: TestData) -
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_freeze_path_exclude_user(
     tmpdir: Path, script: PipTestEnvironment, data: TestData
 ) -> None:

tests/functional/test_install.py

@@ -171,7 +171,7 @@ def test_pep518_allows_missing_requires(
     assert result.files_created
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_pep518_with_user_pip(
     script: PipTestEnvironment, pip_src: Path, data: TestData, common_wheels: Path
 ) -> None:
@@ -2106,7 +2106,7 @@ def test_target_install_ignores_distutils_config_install_prefix(
     result.did_not_create(relative_script_base)
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_user_config_accepted(script: PipTestEnvironment) -> None:
     # user set in the config file is parsed as 0/1 instead of True/False.
     # Check that this doesn't cause a problem.

tests/functional/test_install_reqs.py

@@ -305,8 +305,7 @@ def test_install_local_with_subdirectory(script: PipTestEnvironment) -> None:
     result.assert_installed("version_subpkg.py", editable=False)
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("with_wheel")
+@pytest.mark.usefixtures("enable_user_site", "with_wheel")
 def test_wheel_user_with_prefix_in_pydistutils_cfg(
     script: PipTestEnvironment, data: TestData
 ) -> None:

tests/functional/test_install_user.py

@@ -35,9 +35,9 @@ def dist_in_site_packages(dist):
     )
 
 
+@pytest.mark.usefixtures("enable_user_site")
 class Tests_UserSite:
     @pytest.mark.network
-    @pytest.mark.incompatible_with_test_venv
     def test_reset_env_system_site_packages_usersite(
         self, script: PipTestEnvironment
     ) -> None:
@@ -57,7 +57,6 @@ def test_reset_env_system_site_packages_usersite(
     @pytest.mark.xfail
     @pytest.mark.network
     @need_svn
-    @pytest.mark.incompatible_with_test_venv
     def test_install_subversion_usersite_editable_with_distribute(
         self, script: PipTestEnvironment, tmpdir: Path
     ) -> None:
@@ -77,7 +76,6 @@ def test_install_subversion_usersite_editable_with_distribute(
         )
         result.assert_installed("INITools", use_user_site=True)
 
-    @pytest.mark.incompatible_with_test_venv
     @pytest.mark.usefixtures("with_wheel")
     def test_install_from_current_directory_into_usersite(
         self, script: PipTestEnvironment, data: TestData
@@ -123,7 +121,6 @@ def test_install_user_venv_nositepkgs_fails(
         )
 
     @pytest.mark.network
-    @pytest.mark.incompatible_with_test_venv
     def test_install_user_conflict_in_usersite(
         self, script: PipTestEnvironment
     ) -> None:
@@ -148,7 +145,6 @@ def test_install_user_conflict_in_usersite(
         result2.did_create(egg_info_folder)
         assert not isfile(initools_v3_file), initools_v3_file
 
-    @pytest.mark.incompatible_with_test_venv
     def test_install_user_conflict_in_globalsite(
         self, virtualenv: VirtualEnvironment, script: PipTestEnvironment
     ) -> None:
@@ -191,7 +187,6 @@ def test_install_user_conflict_in_globalsite(
         assert isdir(dist_info_folder)
         assert isdir(initools_folder)
 
-    @pytest.mark.incompatible_with_test_venv
     def test_upgrade_user_conflict_in_globalsite(
         self, virtualenv: VirtualEnvironment, script: PipTestEnvironment
     ) -> None:
@@ -235,7 +230,6 @@ def test_upgrade_user_conflict_in_globalsite(
         assert isdir(dist_info_folder), result2.stdout
         assert isdir(initools_folder)
 
-    @pytest.mark.incompatible_with_test_venv
     def test_install_user_conflict_in_globalsite_and_usersite(
         self, virtualenv: VirtualEnvironment, script: PipTestEnvironment
     ) -> None:
@@ -294,7 +288,6 @@ def test_install_user_conflict_in_globalsite_and_usersite(
         assert isdir(initools_folder)
 
     @pytest.mark.network
-    @pytest.mark.incompatible_with_test_venv
     def test_install_user_in_global_virtualenv_with_conflict_fails(
         self, script: PipTestEnvironment
     ) -> None:

tests/functional/test_install_wheel.py

@@ -406,8 +406,7 @@ def test_wheel_record_lines_have_updated_hash_for_scripts(
     ]
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("with_wheel")
+@pytest.mark.usefixtures("enable_user_site", "with_wheel")
 def test_install_user_wheel(
     script: PipTestEnvironment, shared_data: TestData, tmpdir: Path
 ) -> None:

tests/functional/test_list.py

@@ -129,7 +129,7 @@ def test_multiple_exclude_and_normalization(
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_user_flag(script: PipTestEnvironment, data: TestData) -> None:
     """
     Test the behavior of --user flag in the list command
@@ -144,7 +144,7 @@ def test_user_flag(script: PipTestEnvironment, data: TestData) -> None:
 
 
 @pytest.mark.network
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_user_columns_flag(script: PipTestEnvironment, data: TestData) -> None:
     """
     Test the behavior of --user --format=columns flags in the list command
@@ -656,7 +656,7 @@ def test_list_path(tmpdir: Path, script: PipTestEnvironment, data: TestData) ->
     assert {"name": "simple", "version": "2.0"} in json_result
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_list_path_exclude_user(
     tmpdir: Path, script: PipTestEnvironment, data: TestData
 ) -> None:

tests/functional/test_new_resolver_user.py

@@ -7,7 +7,7 @@
 from tests.lib.venv import VirtualEnvironment
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_new_resolver_install_user(script: PipTestEnvironment) -> None:
     create_basic_wheel_for_package(script, "base", "0.1.0")
     result = script.pip(
@@ -22,7 +22,7 @@ def test_new_resolver_install_user(script: PipTestEnvironment) -> None:
     result.did_create(script.user_site / "base")
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_new_resolver_install_user_satisfied_by_global_site(
     script: PipTestEnvironment,
 ) -> None:
@@ -53,7 +53,7 @@ def test_new_resolver_install_user_satisfied_by_global_site(
     result.did_not_create(script.user_site / "base")
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_new_resolver_install_user_conflict_in_user_site(
     script: PipTestEnvironment,
 ) -> None:
@@ -91,7 +91,7 @@ def test_new_resolver_install_user_conflict_in_user_site(
     result.did_not_create(base_2_dist_info)
 
 
-@pytest.mark.incompatible_with_test_venv
+@pytest.mark.usefixtures("enable_user_site")
 def test_new_resolver_install_user_in_virtualenv_with_conflict_fails(
     script: PipTestEnvironment,
 ) -> None:
@@ -141,8 +141,7 @@ def dist_in_site_packages(dist):
     )
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("patch_dist_in_site_packages")
+@pytest.mark.usefixtures("enable_user_site", "patch_dist_in_site_packages")
 def test_new_resolver_install_user_reinstall_global_site(
     script: PipTestEnvironment,
 ) -> None:
@@ -177,8 +176,7 @@ def test_new_resolver_install_user_reinstall_global_site(
     assert "base" in site_packages_content
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("patch_dist_in_site_packages")
+@pytest.mark.usefixtures("enable_user_site", "patch_dist_in_site_packages")
 def test_new_resolver_install_user_conflict_in_global_site(
     script: PipTestEnvironment,
 ) -> None:
@@ -215,8 +213,7 @@ def test_new_resolver_install_user_conflict_in_global_site(
     assert "base-1.0.0.dist-info" in site_packages_content
 
 
-@pytest.mark.incompatible_with_test_venv
-@pytest.mark.usefixtures("patch_dist_in_site_packages")
+@pytest.mark.usefixtures("enable_user_site", "patch_dist_in_site_packages")
 def test_new_resolver_install_user_conflict_in_global_and_user_sites(
     script: PipTestEnvironment,
 ) -> None: