1 files changed, 65 insertions, 0 deletions
diff --git a/tests/test_memfs.py b/tests/test_memfs.py
new file mode 100644
index 0000000..0555726
--- /dev/null
+++ b/tests/test_memfs.py
@@ -0,0 +1,65 @@
+import logging
+from concurrent.futures import ThreadPoolExecutor
+from contextlib import ExitStack
+from unittest import TestCase, mock
+from uuid import uuid4
+
+from snekbox.memfs import MemFS
+
+UUID_TEST = uuid4()
+
+
+class MemFSTests(TestCase):
+    def setUp(self):
+        super().setUp()
+        self.logger = logging.getLogger("snekbox.memfs")
+        self.logger.setLevel(logging.WARNING)
+
+    @mock.patch("snekbox.memfs.uuid4", lambda: UUID_TEST)
+    def test_assignment_thread_safe(self):
+        """Test concurrent mounting works in multi-thread environments."""
+        # Concurrently create MemFS in threads, check only 1 can be created
+        # Others should result in RuntimeError
+        with ExitStack() as stack:
+            with ThreadPoolExecutor() as executor:
+                memfs: MemFS | None = None
+                # Each future uses enter_context to ensure __exit__ on test exception
+                futures = [
+                    executor.submit(lambda: stack.enter_context(MemFS(10))) for _ in range(8)
+                ]
+                for future in futures:
+                    # We should have exactly one result and all others RuntimeErrors
+                    if err := future.exception():
+                        self.assertIsInstance(err, RuntimeError)
+                    else:
+                        self.assertIsNone(memfs)
+                        memfs = future.result()
+
+                # Original memfs should still exist afterwards
+                self.assertIsInstance(memfs, MemFS)
+                self.assertTrue(memfs.path.is_mount())
+
+    def test_cleanup(self):
+        """Test explicit cleanup."""
+        memfs = MemFS(10)
+        path = memfs.path
+        self.assertTrue(path.is_mount())
+        memfs.cleanup()
+        self.assertFalse(path.exists())
+
+    def test_context_cleanup(self):
+        """Context __exit__ should trigger cleanup."""
+        with MemFS(10) as memfs:
+            path = memfs.path
+            self.assertTrue(path.is_mount())
+        self.assertFalse(path.exists())
+
+    def test_implicit_cleanup(self):
+        """Test implicit _cleanup triggered by GC."""
+        memfs = MemFS(10)
+        path = memfs.path
+        self.assertTrue(path.is_mount())
+        # Catch the warning about implicit cleanup
+        with self.assertWarns(ResourceWarning):
+            del memfs
+        self.assertFalse(path.exists())