tests: Add xfail_windows decorator for failing tests on windows

lib/imagery/testsuite/test_imagery_signature_management.py

@@ -15,6 +15,7 @@
 
 from grass.gunittest.case import TestCase
 from grass.gunittest.main import test
+from grass.gunittest.utils import xfail_windows
 
 from grass.script.core import tempname
 import grass.script as gs
@@ -44,6 +45,7 @@
 
 
 class GetSignaturesDirTestCase(TestCase):
+    @xfail_windows
     def test_get_sig(self):
         cdir = ctypes.create_string_buffer(GNAME_MAX)
         I_get_signatures_dir(cdir, I_SIGFILE_TYPE_SIG)
@@ -54,6 +56,7 @@ def test_get_sigset(self):
         I_get_signatures_dir(cdir, I_SIGFILE_TYPE_SIGSET)
         self.assertEqual(utils.decode(cdir.value), f"signatures{HOST_DIRSEP}sigset")
 
+    @xfail_windows
     def test_get_libsvm(self):
         elem = ctypes.create_string_buffer(GNAME_MAX)
         I_get_signatures_dir(elem, I_SIGFILE_TYPE_LIBSVM)

python/grass/gunittest/utils.py

@@ -14,6 +14,9 @@
 from pathlib import Path
 import shutil
 import sys
+from unittest import expectedFailure
+import warnings
+
 
 
 def ensure_dir(directory):
@@ -80,3 +83,15 @@ def safe_repr(obj, short=False):
     if not short or len(result) < _MAX_LENGTH:
         return result
     return result[:_MAX_LENGTH] + " [truncated]..."
+
+
+def xfail_windows(test_item):
+    """Marks a test as an expected failure or error only on Windows
+    Equivalent to applying @unittest.expectedFailure only when running
+    on Windows.
+    """
+    if not sys.platform.startswith("win"):
+        return lambda func: func
+    # warnings.warn("Once the test is fixed and passing, remove the "
+    #    "@xfail_windows decorator", stacklevel=2)
+    return expectedFailure(test_item)