6804 enhance compose input check

monai/transforms/compose.py

@@ -235,6 +235,13 @@ def __init__(
     ) -> None:
         if transforms is None:
             transforms = []
+
+        if not isinstance(map_items, bool):
+            raise ValueError(
+                f"Argument 'map_items' should be boolean. Got {type(map_items)}."
+                "Check brackets when passing a sequence of callables."
+            )
+
         self.transforms = ensure_tuple(transforms)
         self.map_items = map_items
         self.unpack_items = unpack_items

tests/test_compose.py

@@ -641,5 +641,17 @@ def test_compose_execute_equivalence_with_flags(self, flags, data, pipeline):
                 self.assertTrue(expected, actual)
 
 
+class TestComposeCallableInput(unittest.TestCase):
+    def test_value_error_when_not_sequence(self):
+        data = torch.tensor(np.random.randn(1, 5, 5))
+
+        xform = mt.Compose([mt.Flip(0), mt.Flip(0)])
+        res = xform(data)
+        np.testing.assert_allclose(data, res, atol=1e-3)
+
+        with self.assertRaises(ValueError):
+            mt.Compose(mt.Flip(0), mt.Flip(0))(data)
+
+
 if __name__ == "__main__":
     unittest.main()