ENH: testing: add dlpack conversion support (#749)

* Adding  dlpack conversion support

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* precommit error fix

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* precommit error fix

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>

* fix lint

* remove comment

---------

Signed-off-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: Pradyot Ranjan <99216956+pradyotRanjan@users.noreply.github.com>
Co-authored-by: Lucas Colley <lucas.colley8@gmail.com>

Author: prady0t

src/array_api_extra/_lib/_testing.py

@@ -136,6 +136,12 @@ def as_numpy_array(array: Array, *, xp: ModuleType) -> np.typing.NDArray[Any]:
         cpu = cast(Device, jax.devices("cpu")[0])
         array = to_device(array, cpu)
 
+    if hasattr(array, "__dlpack__"):
+        try:
+            return np.from_dlpack(array)  # type: ignore[arg-type]  # pyright: ignore[reportArgumentType]
+        except (TypeError, BufferError):
+            pass
+
     return np.asarray(array)