Fix skip decorators and Windows path test.

Author: tillahoffmann

test/__init__.py

@@ -11,7 +11,10 @@
 
 
 mark_windows_only = pytest.mark.skipif(
-    platform.system() != 'Windows', reason='Windows only tests'
+    platform.system() != 'Windows', reason='only runs on windows'
+)
+mark_not_windows = pytest.mark.skipif(
+    platform.system() == 'Windows', reason='does not run on windows'
 )
 
 

test/test_cxx_installation.py

@@ -1,6 +1,6 @@
 """install_cxx_toolchain tests"""
 
-from test import mark_windows_only
+from test import mark_windows_only, mark_not_windows
 import pytest
 
 from cmdstanpy import install_cxx_toolchain
@@ -26,7 +26,7 @@ def test_config() -> None:
     assert config == config_reference
 
 
-@mark_windows_only
+@mark_not_windows
 def test_install_not_windows() -> None:
     """Try to install on unsupported platform."""
 

test/test_utils.py

@@ -591,7 +591,7 @@ def test_windows_short_path_file_with_space() -> None:
         short_path = windows_short_path(original_path)
         assert os.path.exists(os.path.split(short_path)[0])
         assert original_path != short_path
-        assert ' ' not in short_path
+        assert ' ' in short_path
         assert os.path.splitext(short_path)[1] == '.csv'