Pass data_format through TransformBoundsWrapper (#529)

* Make data format accessible through wrapper

* Fix type

* Increase test coverage

* Use correct types

foolbox/models/base.py

@@ -64,6 +64,10 @@ def _preprocess(self, inputs: ep.TensorType) -> ep.TensorType:
         min_, max_ = self._model.bounds
         return x * (max_ - min_) + min_
 
+    @property
+    def data_format(self) -> Any:
+        return getattr(self._model, "data_format", None)
+
 
 ModelType = TypeVar("ModelType", bound="ModelWithPreprocessing")
 

tests/test_attacks_base.py

@@ -45,3 +45,21 @@ class Model:
     model.data_format = "invalid"  # type: ignore
     with pytest.raises(ValueError):
         assert fbn.attacks.base.get_channel_axis(model, 3)  # type: ignore
+
+
+def test_transform_bounds_wrapper_data_format() -> None:
+    class Model(fbn.models.Model):
+        data_format = "channels_first"
+
+        @property
+        def bounds(self) -> fbn.types.Bounds:
+            return fbn.types.Bounds(0, 1)
+
+        def __call__(self, inputs: fbn.models.base.T) -> fbn.models.base.T:
+            return inputs
+
+    model = Model()
+    wrapped_model = fbn.models.TransformBoundsWrapper(model, (0, 1))
+    assert fbn.attacks.base.get_channel_axis(
+        model, 3
+    ) == fbn.attacks.base.get_channel_axis(wrapped_model, 3)