Test functional_collectives import (#318)

Summary:
Avoid breakages when FC can't import under multipy.

Pull Request resolved: #318

Reviewed By: PaliC

Differential Revision: D45540107

Pulled By: wconstab

fbshipit-source-id: 9a24bdbfad64f8b3635840a8195fb573e3dfb283

Author: wconstab

multipy/runtime/test_compat.py

@@ -59,6 +59,12 @@ def fn(x, y):
         c_fn = torch.compile(fn)
         c_fn(torch.randn(10), torch.randn(10))
 
+    def test_functional_collectives(self):
+        with self.assertWarns(Warning):
+            # Functional collectives don't work with torchdeploy
+            # but we want to make sure the import doesn't totally crash
+            import torch.distributed._functional_collectives
+
 
 if __name__ == "__main__":
     unittest.main()