Ensure os.stat returns consistent result in mocked unit tests

mons/commands/main.py

@@ -357,7 +357,7 @@ def determine_configuration(srcdir: fs.Directory):
         # Artifact still has to be shared between all projects
         newest_artifact, _ = max(
             (
-                (output, os.stat(fs.joindir(srcdir, proj, "bin", output)))
+                (output, os.stat(fs.joindir(srcdir, proj, "bin", output)).st_mtime_ns)
                 for proj in artifacts.keys()
                 for output in common_outputs
             ),

tests/conftest.py

@@ -162,11 +162,14 @@ def mock_filesystem(request, tmp_path):
         yield root
         return
 
+    paths = list()
+
     def create_fs(root, mockup):
         if isinstance(mockup, dict):
             for dir, contents in mockup.items():
                 path = os.path.join(root, dir)
                 os.mkdir(path)
+                paths.append(path)
                 create_fs(path, contents)
         elif isinstance(mockup, (list, tuple)):
             for node in mockup:
@@ -179,6 +182,12 @@ def create_fs(root, mockup):
             else:
                 with open(path, "x"):
                     pass
+            paths.append(path)
 
     create_fs(root, mockup)
+
+    # set consistent last modified/accessed times for created paths
+    for i, path in enumerate(paths):
+        os.utime(path, (i, i))
+
     yield os.walk(root) if walk else root

tests/integration/test_main_install.py

@@ -85,7 +85,6 @@ def test_determine_configuration_no_common(caplog, mock_filesystem):
 )
 def test_determine_configuration_most_recent(caplog, mock_filesystem):
     with caplog.at_level(logging.DEBUG, main.__name__):
-        # result may be inconsistent because files are created so close together.
         assert main.determine_configuration(mock_filesystem) == "RELEASE/net452"
         assert "Most recent" in caplog.text