Add check on measurement names

Add a check when specifying measurement names that they do not contain
characters that will be a problem for avro schemas.

python/lsst/analysis/tools/interfaces/_stages.py

@@ -22,6 +22,7 @@
 
 __all__ = ("BasePrep", "BaseProcess", "BaseMetricAction", "BaseProduce")
 
+import logging
 from collections import abc
 from typing import Any, cast
 
@@ -44,6 +45,8 @@
 )
 from ._interfaces import KeyedData, KeyedDataSchema, KeyedDataTypes, Scalar, Vector
 
+_LOG = logging.getLogger(__name__)
+
 
 class BasePrep(KeyedDataAction):
     """Base class for actions which prepare data for processing."""
@@ -182,13 +185,26 @@ def __call__(self, data: KeyedData, **kwargs) -> KeyedData:
         return results
 
 
+def _newNameChecker(value: str) -> bool:
+    if "-" in value:
+        # Yes this should be a log here, as pex config provides no other
+        # useful way to get info into the exception.
+        _LOG.error("Remapped metric names must not have a - character in them.")
+        return False
+    return True
+
+
 class BaseMetricAction(MetricAction):
     """Base class for actions which compute metrics."""
 
     units = DictField[str, str](doc="Mapping of scalar key to astropy unit string", default={})
     newNames = DictField[str, str](
-        doc="Mapping of key to new name if needed prior to creating metric",
+        doc=(
+            "Mapping of key to new name if needed prior to creating metric, "
+            "cannot contain a minus character in the name."
+        ),
         default={},
+        itemCheck=_newNameChecker,
     )
 
     def getInputSchema(self) -> KeyedDataSchema:

tests/test_analysisTool.py

@@ -86,6 +86,15 @@ def testFinalize(self):
         self.assertEqual(self.e.name, "BE_final")
 
 
+class TestMetricNameValidation(TestCase):
+    """Test that disallowed characters in measurement names are filtered."""
+
+    def testMinusNameFails(self):
+        tool = AnalysisTool()
+        with self.assertRaises(pexConfig.FieldValidationError):
+            tool.produce.metric.newNames = {"something": "not-allowed"}
+
+
 class LoadFromPipelineTestCase(TestCase):
     """Test that analysis tools can be loaded from a pipeline"""