Add test case for explicitly disallowed __iter__ and __contains__

test/test_no_iter_contains.py

@@ -0,0 +1,34 @@
+import os
+import tempfile
+import unittest
+
+import netCDF4
+
+FILE_NAME = tempfile.NamedTemporaryFile(suffix='.nc', delete=False).name
+
+
+class TestNoIterNoContains(unittest.TestCase):
+    def setUp(self) -> None:
+        self.file = FILE_NAME
+        with netCDF4.Dataset(self.file, "w") as dataset:
+            # just create a simple variable
+            dataset.createVariable("var1", int)
+
+    def tearDown(self) -> None:
+        os.remove(self.file)
+
+    def test_no_iter(self) -> None:
+        """Verify that iteration is explicitly not supported"""
+        with netCDF4.Dataset(self.file, "r") as dataset:
+            with self.assertRaises(TypeError):
+                for _ in dataset:  # type: ignore  # type checker catches that this doesn't work
+                    pass
+
+    def test_no_contains(self) -> None:
+        """Verify the membership operations are explicity not supported"""
+        with netCDF4.Dataset(self.file, "r") as dataset:
+            with self.assertRaises(TypeError):
+                _ = "var1" in dataset
+
+if __name__ == "__main__":
+    unittest.main(verbosity=2)