Fix dataset equality checks (#2077)

Summary:
Pull Request resolved: #2077

This was erroring out when self.Yvar was a tensor but other.Yvar was None. Updated to equality checks to handle this case.

Reviewed By: Balandat, esantorella

Differential Revision: D50818635

fbshipit-source-id: 024e2c12160137202ea1deee2d96e165ef816afc

Author: saitcakmak

botorch/utils/datasets.py

@@ -144,7 +144,7 @@ def __eq__(self, other: Any) -> bool:
             and (
                 other.Yvar is None
                 if self.Yvar is None
-                else torch.equal(self.Yvar, other.Yvar)
+                else other.Yvar is not None and torch.equal(self.Yvar, other.Yvar)
             )
             and self.feature_names == other.feature_names
             and self.outcome_names == other.outcome_names

test/utils/test_datasets.py

@@ -118,6 +118,11 @@ def test_supervised(self):
         self.assertIsInstance(dataset.Yvar, Tensor)
         self.assertIsInstance(dataset._Yvar, DenseContainer)
 
+        # More equality checks with & without Yvar.
+        self.assertEqual(dataset, dataset)
+        self.assertNotEqual(dataset, dataset2)
+        self.assertNotEqual(dataset2, dataset)
+
     def test_fixedNoise(self):
         # Generate some data
         X = rand(3, 2)