Drop the hacky appdirs tests

There is no reason to try to test for other platforms.

Author: pradyunsg

tests/unit/test_appdirs.py

@@ -1,8 +1,5 @@
-import ntpath
 import os
-import posixpath
 import sys
-from typing import Generator
 from unittest import mock
 
 import pytest
@@ -11,50 +8,8 @@
 from pip._internal.utils import appdirs
 
 
-@pytest.fixture()
-def platformdirs_win32(monkeypatch: pytest.MonkeyPatch) -> Generator[None, None, None]:
-
-    # Monkeypatch platformdirs to pretend we're running on Windows
-
-    with monkeypatch.context() as m:
-        m.setattr(sys, "platform", "win32")
-        m.setattr(os, "path", ntpath)
-        platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-        yield
-
-    platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-
-
-@pytest.fixture()
-def platformdirs_darwin(monkeypatch: pytest.MonkeyPatch) -> Generator[None, None, None]:
-
-    # Monkeypatch platformdirs to pretend we're running on macOS
-
-    with monkeypatch.context() as m:
-        m.setattr(sys, "platform", "darwin")
-        m.setattr(os, "path", posixpath)
-        platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-        yield
-
-    platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-
-
-@pytest.fixture()
-def platformdirs_linux(monkeypatch: pytest.MonkeyPatch) -> Generator[None, None, None]:
-
-    # Monkeypatch platformdirs to pretend we're running on Linux
-
-    with monkeypatch.context() as m:
-        m.setattr(sys, "platform", "linux")
-        m.setattr(os, "path", posixpath)
-        platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-        yield
-
-    platformdirs.PlatformDirs = platformdirs._set_platform_dir_class()
-
-
 class TestUserCacheDir:
-    @pytest.mark.usefixtures("platformdirs_win32")
+    @pytest.mark.skipif(sys.platform != "win32", reason="Windows-only test")
     def test_user_cache_dir_win(self, monkeypatch: pytest.MonkeyPatch) -> None:
         _get_win_folder = mock.Mock(return_value="C:\\Users\\test\\AppData\\Local")
 
@@ -71,20 +26,20 @@ def test_user_cache_dir_win(self, monkeypatch: pytest.MonkeyPatch) -> None:
         )
         assert _get_win_folder.call_args_list == [mock.call("CSIDL_LOCAL_APPDATA")]
 
-    @pytest.mark.usefixtures("platformdirs_darwin")
+    @pytest.mark.skipif(sys.platform != "darwin", reason="MacOS-only test")
     def test_user_cache_dir_osx(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.setenv("HOME", "/home/test")
 
         assert appdirs.user_cache_dir("pip") == "/home/test/Library/Caches/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_cache_dir_linux(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.delenv("XDG_CACHE_HOME", raising=False)
         monkeypatch.setenv("HOME", "/home/test")
 
         assert appdirs.user_cache_dir("pip") == "/home/test/.cache/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_cache_dir_linux_override(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -93,7 +48,7 @@ def test_user_cache_dir_linux_override(
 
         assert appdirs.user_cache_dir("pip") == "/home/test/.other-cache/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_cache_dir_linux_home_slash(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -125,7 +80,7 @@ def my_get_win_folder(csidl_name):
 
 
 class TestSiteConfigDirs:
-    @pytest.mark.usefixtures("platformdirs_win32")
+    @pytest.mark.skipif(sys.platform != "win32", reason="Windows-only test")
     def test_site_config_dirs_win(self, monkeypatch: pytest.MonkeyPatch) -> None:
         _get_win_folder = mock.Mock(return_value="C:\\ProgramData")
 
@@ -139,7 +94,7 @@ def test_site_config_dirs_win(self, monkeypatch: pytest.MonkeyPatch) -> None:
         assert appdirs.site_config_dirs("pip") == ["C:\\ProgramData\\pip"]
         assert _get_win_folder.call_args_list == [mock.call("CSIDL_COMMON_APPDATA")]
 
-    @pytest.mark.usefixtures("platformdirs_darwin")
+    @pytest.mark.skipif(sys.platform != "darwin", reason="MacOS-only test")
     def test_site_config_dirs_osx(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.setenv("HOME", "/home/test")
 
@@ -148,13 +103,13 @@ def test_site_config_dirs_osx(self, monkeypatch: pytest.MonkeyPatch) -> None:
             "/Library/Application Support/pip",
         ]
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_site_config_dirs_linux(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.delenv("XDG_CONFIG_DIRS", raising=False)
 
         assert appdirs.site_config_dirs("pip") == ["/etc/xdg/pip", "/etc"]
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_site_config_dirs_linux_override(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -168,7 +123,7 @@ def test_site_config_dirs_linux_override(
             "/etc",
         ]
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_site_config_dirs_linux_empty(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -178,7 +133,7 @@ def test_site_config_dirs_linux_empty(
 
 
 class TestUserConfigDir:
-    @pytest.mark.usefixtures("platformdirs_win32")
+    @pytest.mark.skipif(sys.platform != "win32", reason="Windows-only test")
     def test_user_config_dir_win_no_roaming(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -197,7 +152,7 @@ def test_user_config_dir_win_no_roaming(
         )
         assert _get_win_folder.call_args_list == [mock.call("CSIDL_LOCAL_APPDATA")]
 
-    @pytest.mark.usefixtures("platformdirs_win32")
+    @pytest.mark.skipif(sys.platform != "win32", reason="Windows-only test")
     def test_user_config_dir_win_yes_roaming(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -215,7 +170,7 @@ def test_user_config_dir_win_yes_roaming(
         )
         assert _get_win_folder.call_args_list == [mock.call("CSIDL_APPDATA")]
 
-    @pytest.mark.usefixtures("platformdirs_darwin")
+    @pytest.mark.skipif(sys.platform != "darwin", reason="MacOS-only test")
     def test_user_config_dir_osx(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.setenv("HOME", "/home/test")
 
@@ -227,14 +182,14 @@ def test_user_config_dir_osx(self, monkeypatch: pytest.MonkeyPatch) -> None:
         else:
             assert appdirs.user_config_dir("pip") == "/home/test/.config/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_config_dir_linux(self, monkeypatch: pytest.MonkeyPatch) -> None:
         monkeypatch.delenv("XDG_CONFIG_HOME", raising=False)
         monkeypatch.setenv("HOME", "/home/test")
 
         assert appdirs.user_config_dir("pip") == "/home/test/.config/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_config_dir_linux_override(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None:
@@ -243,7 +198,7 @@ def test_user_config_dir_linux_override(
 
         assert appdirs.user_config_dir("pip") == "/home/test/.other-config/pip"
 
-    @pytest.mark.usefixtures("platformdirs_linux")
+    @pytest.mark.skipif(sys.platform != "linux", reason="Linux-only test")
     def test_user_config_dir_linux_home_slash(
         self, monkeypatch: pytest.MonkeyPatch
     ) -> None: