Added test in dynamo directory to check that the original and final e…

…rror messages are both not obscured in the case that an exception happens. Also added a test for when an exception is not raised for completeness

test/dynamo/test_same_allclose.py

@@ -0,0 +1,25 @@
+import unittest
+import torch
+from torch._dynamo.testing import same
+
+class TestSameAllclose(unittest.TestCase):
+    def test_same_allclose_exception(self):
+        ref = torch.tensor([1.0, 2.0, 3.0])
+        res = torch.tensor([1.0, 2.0, float('nan')])
+
+        try:
+            same(ref, res, equal_nan=False)
+        except RuntimeError as e:
+            self.assertIn("An unexpected error occurred while comparing tensors with torch.allclose", str(e))
+            self.assertIn("RuntimeError: The size of tensor a (3) must match the size of tensor b (3) at non-singleton dimension 0", str(e))
+        else:
+            self.fail("RuntimeError not raised")
+
+    def test_same_allclose_no_exception(self):
+        ref = torch.tensor([1.0, 2.0, 3.0])
+        res = torch.tensor([1.0, 2.0, 3.0])
+
+        self.assertTrue(same(ref, res))
+
+if __name__ == '__main__':
+    unittest.main()