update tests for MergeRepeatedMeasurements (#1607)

Summary:
Pull Request resolved: #1607

updates per comments after landing D45558427

Reviewed By: esantorella

Differential Revision: D45608725

fbshipit-source-id: 2ee32e87e575af7b8dbe5ecba6688a8104170e7f

Author: sdaulton

ax/modelbridge/tests/test_merge_repeated_measurements_transform.py

@@ -18,14 +18,16 @@ def compare_obs(
     test.assertEqual(obs1.data.metric_names, obs2.data.metric_names)
     test.assertTrue(np.array_equal(obs1.data.means, obs2.data.means))
     discrep = np.max(np.abs(obs1.data.covariance - obs2.data.covariance))
-    test.assertTrue(discrep <= discrepancy_tol)
-    test.assertTrue(obs1.features.parameters == obs2.features.parameters)
+    test.assertLessEqual(discrep, discrepancy_tol)
+    test.assertEqual(obs1.features.parameters, obs2.features.parameters)
 
 
 class MergeRepeatedMeasurementsTransformTest(TestCase):
     def testTransform(self) -> None:
         obs_feats1 = ObservationFeatures(parameters={"a": 0.0})
-        with self.assertRaises(RuntimeError):
+        with self.assertRaisesRegex(
+            RuntimeError, "MergeRepeatedMeasurements requires observations"
+        ):
             # test that observations are required
             MergeRepeatedMeasurements()
         # test nan in covariance
@@ -37,7 +39,9 @@ def testTransform(self) -> None:
             ),
             features=obs_feats1,
         )
-        with self.assertRaises(NotImplementedError):
+        with self.assertRaisesRegex(
+            NotImplementedError, "All metrics must have noise observations."
+        ):
             MergeRepeatedMeasurements(observations=[observation])
         # test full covariance
         observation = Observation(
@@ -48,7 +52,9 @@ def testTransform(self) -> None:
             ),
             features=obs_feats1,
         )
-        with self.assertRaises(NotImplementedError):
+        with self.assertRaisesRegex(
+            NotImplementedError, "Only independent metrics are currently supported."
+        ):
             MergeRepeatedMeasurements(observations=[observation])
 
         # test noiseless, different means
@@ -71,7 +77,11 @@ def testTransform(self) -> None:
                 features=obs_feats1,
             ),
         ]
-        with self.assertRaises(ValueError):
+        with self.assertRaisesRegex(
+            ValueError,
+            "All repeated arms with noiseless measurements "
+            "must have the same means.",
+        ):
             MergeRepeatedMeasurements(observations=observations)
         # test noiseless, same means
         observations = [

ax/modelbridge/transforms/merge_repeated_measurements.py

@@ -44,7 +44,6 @@ def __init__(
             str, DefaultDict[str, DefaultDict[str, List[float]]]
         ] = defaultdict(lambda: defaultdict(lambda: defaultdict(list)))
         observation_features, observation_data = separate_observations(observations)
-        #
         for j, obsd in enumerate(observation_data):
             # This intentionally ignores the trial index
             key = Arm.md5hash(observation_features[j].parameters)