DM-15455: Support trailing text in file template format string

python/lsst/daf/butler/core/fileTemplates.py

@@ -151,6 +151,10 @@ def format(self, ref):
             if field_name == "component":
                 usedComponent = True
 
+            if format_spec is None:
+                output = output + literal
+                continue
+
             if "?" in format_spec:
                 optional = True
                 # Remove the non-standard character from the spec

python/lsst/daf/butler/registries/sqlRegistry.py

@@ -346,8 +346,8 @@ def addDataset(self, datasetType, dataId, run, producer=None):
 
         Parameters
         ----------
-        datasetType : `str`
-            Name of a `DatasetType`.
+        datasetType : `DatasetType`
+            Type of the Dataset.
         dataId : `dict`
             A `dict` of `DataUnit` link name, value pairs that label the
             `DatasetRef` within a collection.
@@ -381,8 +381,8 @@ def addDataset(self, datasetType, dataId, run, producer=None):
         # Then again, it is undoubtedly not the only place where
         # this problem occurs. Needs some serious thought.
         if self.find(run.collection, datasetType, dataId) is not None:
-            raise ValueError("A dataset with id: {} already exists in collection {}".format(
-                dataId, run.collection))
+            raise ValueError("A dataset of type {} with id: {} already exists in collection {}".format(
+                datasetType, dataId, run.collection))
         datasetTable = self._schema.tables["Dataset"]
         datasetRef = None
         # TODO add producer

tests/test_sqlRegistry.py

@@ -98,6 +98,8 @@ def testDataset(self):
         outRef = registry.getDataset(ref.id)
         self.assertIsNotNone(ref.id)
         self.assertEqual(ref, outRef)
+        with self.assertRaises(ValueError):
+            ref = registry.addDataset(datasetType, dataId={"camera": "DummyCam"}, run=run)
 
     def testComponents(self):
         registry = Registry.fromConfig(self.butlerConfig, create=True)

tests/test_templates.py

@@ -53,6 +53,10 @@ def testBasic(self):
         self.assertTemplate(tmplstr,
                             "calexp/00052/U",
                             self.makeDatasetRef("calexp"))
+        tmplstr = "{datasetType}/{visit:05d}/{filter}-trail"
+        self.assertTemplate(tmplstr,
+                            "calexp/00052/U-trail",
+                            self.makeDatasetRef("calexp"))
 
     def testOptional(self):
         """Optional units in templates."""