Add a new test to read a TTree file and output an RNTuple file

test/k4FWCoreTest/CMakeLists.txt

@@ -137,13 +137,13 @@ add_test_with_env(FunctionalCollectionMerger options/ExampleFunctionalCollection
 add_test_with_env(FunctionalFilterFile options/ExampleFunctionalFilterFile.py)
 add_test_with_env(FunctionalMetadata options/ExampleFunctionalMetadata.py)
 add_test_with_env(FunctionalMetadataOldAlgorithm options/ExampleFunctionalMetadataOldAlgorithm.py)
-
 add_test_with_env(FunctionalWrongImport options/ExampleFunctionalWrongImport.py)
 set_tests_properties(FunctionalWrongImport PROPERTIES PASS_REGULAR_EXPRESSION "ImportError: Importing ApplicationMgr or IOSvc from Configurables is not allowed.")
 add_test_with_env(FunctionalProducerRNTuple options/ExampleFunctionalProducerRNTuple.py)
+add_test_with_env(FunctionalTTreeToRNTuple options/ExampleFunctionalTTreeToRNTuple.py)
 
 add_test(NAME FunctionalCheckFiles COMMAND python3 ${CMAKE_CURRENT_LIST_DIR}/options/CheckOutputFiles.py)
-set_tests_properties(FunctionalCheckFiles PROPERTIES DEPENDS "FunctionalFile;FunctionalMTFile;FunctionalMultipleFile;FunctionalOutputCommands;FunctionalProducerAbsolutePath;FunctionalTransformerRuntimeEmpty;FunctionalMix;FunctionalMixIOSvc;FunctionalTransformerHist;FunctionalCollectionMerger;FunctionalFilterFile;FunctionalMetadata;FunctionalMetadataOldAlgorithm;FunctionalProducerRNTuple;FunctionalReadNthEvent")
+set_tests_properties(FunctionalCheckFiles PROPERTIES DEPENDS "FunctionalFile;FunctionalMTFile;FunctionalMultipleFile;FunctionalOutputCommands;FunctionalProducerAbsolutePath;FunctionalTransformerRuntimeEmpty;FunctionalMix;FunctionalMixIOSvc;FunctionalTransformerHist;FunctionalCollectionMerger;FunctionalFilterFile;FunctionalMetadata;FunctionalMetadataOldAlgorithm;FunctionalProducerRNTuple;FunctionalProducerTTreeToRNTuple")
 
 # Do this after checking the files not to overwrite them
 add_test_with_env(FunctionalFile_toolong options/ExampleFunctionalFile.py -n 999 PROPERTIES DEPENDS FunctionalCheckFiles PASS_REGULAR_EXPRESSION

test/k4FWCoreTest/options/CheckOutputFiles.py

@@ -177,10 +177,11 @@ def check_events(filename, number):
         raise RuntimeError(
             f"Metadata parameter {key} does not match the expected value, got {metadata.get_parameter(key)} but expected {value}"
         )
-podio_reader = podio.root_io.RNTupleReader("functional_producer_rntuple.root")
-frames = podio_reader.get("events")
-if len(frames) != 10:
-    raise RuntimeError(f"Expected 10 events but got {len(frames)}")
+for rntuple in ["functional_producer_rntuple.root", "functional_producer_rntuple_converted.root"]:
+    reader = podio.root_io.RNTupleReader(f"{rntuple}")
+    frames = podio_reader.get("events")
+    if len(frames) != 10:
+        raise RuntimeError(f"Expected 10 events but got {len(frames)}")
 
 reader = podio.root_io.Reader("functional_metadata_old_algorithm.root")
 metadata = reader.get("metadata")[0]

test/k4FWCoreTest/options/ExampleFunctionalTTreeToRNTuple.py

@@ -0,0 +1,40 @@
+#
+# Copyright (c) 2014-2024 Key4hep-Project.
+#
+# This file is part of Key4hep.
+# See https://key4hep.github.io/key4hep-doc/ for further info.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# This is an example algorithm to modify a TTree into an RNTuple
+# Don't use! There is already a converter in podio called
+# podio-ttree-to-rntuple
+# Running with k4run will add some extra configuration metadata to the file
+
+from Gaudi.Configuration import INFO
+from Configurables import EventDataSvc
+from k4FWCore import ApplicationMgr, IOSvc
+
+iosvc = IOSvc("IOSvc")
+iosvc.Input = "functional_producer.root"
+iosvc.Output = "functional_producer_rntuple_converted.root"
+iosvc.OutputType = "RNTuple"
+
+ApplicationMgr(
+    TopAlg=[],
+    EvtSel="NONE",
+    EvtMax=10,
+    ExtSvc=[EventDataSvc("EventDataSvc")],
+    OutputLevel=INFO,
+)