Add unit test for Run 3 Scouting formats

DataFormats/Scouting/README.md

@@ -0,0 +1,12 @@
+#  DataFormats/Scouting
+
+## Scouting Data Formats
+
+Any changes to the Scouting data formats must be backwards compatible. In order to ensure the Scouting formats can be read by all future CMSSW releases, there is a `TestRun3ScoutingDataFormats` unit test, which makes use of the `TestReadRun3Scouting` analyzer and the `TestWriteRun3Scouting` producer. The unit test checks that the objects can be read properly from
+
+* a file written by the same release
+* files written by (some) earlier releases
+
+If the persistent format of any Scouting data format gets changed in the future, please adjust the `TestReadRun3Scouting` and `TestWriteRun3Scouting` modules accordingly. It is important that every member container has some content in this test. Please also add a new file to the [https://github.com/cms-data/DataFormats-Scouting/](https://github.com/cms-data/DataFormats-Scouting/) repository, and update the `TestRun3ScoutingDataFormats` unit test to read the newly created file. The file name should contain the version numbers of the data format classes (from classes_def.xml) in alphabetical order and the release or pre-release with which it was written. If the latest file of Run 3 scouting before the update has not been used in data taking, the file can be deleted.
+
+There will probably be analogous tests added in the future for Run 2 and for runs after Run 3 which will need similar maintenance, although it is unlikely the Run 2 formats will change anymore.

DataFormats/Scouting/test/BuildFile.xml

@@ -1,2 +1,13 @@
+<use name="DataFormats/Scouting"/>
+
+<library name="testRun3ScoutingDataFormats" file="TestReadRun3Scouting.cc,TestWriteRun3Scouting.cc">
+  <flags EDM_PLUGIN="1"/>
+  <use name="FWCore/Framework"/>
+  <use name="FWCore/ParameterSet"/>
+  <use name="FWCore/Utilities"/>
+</library>
+
+<test name="TestRun3ScoutingDataFormats" command="TestRun3ScoutingFormats.sh"/>
+
 <test name="testDataFormatsScoutingRun2" command="testDataFormatsScoutingRun2.sh"/>
 <test name="testDataFormatsScoutingRun3" command="testDataFormatsScoutingRun3.sh"/>

DataFormats/Scouting/test/TestRun3ScoutingFormats.sh

@@ -0,0 +1,55 @@
+#!/bin/sh -ex
+
+function die { echo $1: status $2 ;  exit $2; }
+
+LOCAL_TEST_DIR=${SCRAM_TEST_PATH}
+
+cmsRun ${LOCAL_TEST_DIR}/create_Run3Scouting_test_file_cfg.py || die 'Failure using create_Run3Scouting_test_file_cfg.py' $?
+
+file=testRun3Scouting.root
+
+cmsRun ${LOCAL_TEST_DIR}/test_readRun3Scouting_cfg.py "$file" || die "Failure using test_readRun3Scouting_cfg.py $file" $?
+
+# The old files read below were generated as follows.
+#
+#     testRun3Scouting_v3_v5_v3_v4_v5_v3_v5_v3_v3_CMSSW_12_4_0.root:
+#     Check out the 12_4_0 release and cherry pick the commit that
+#     adds the original version of the file
+#     DataFormats/Scouting/test/TestWriteRun3Scouting.cc
+#     (6 files added by that commit). There will be a conflict
+#     with BuildFile.xml and you will need to delete the two
+#     unrelated lines).
+#
+#     testRun3Scouting_v3_v6_v3_v4_v5_v3_v5_v3_v3_CMSSW_13_0_3.root
+#     Check out the 13_0_3 release and cherry pick the commit that
+#     adds the original version of the file
+#     DataFormats/Scouting/test/TestWriteRun3Scouting.cc
+#     (6 files added by that commit). There will be the same
+#     conflict with BuildFile.xml and you will need to delete
+#     the two unrelated lines). Also, add the second commit modifying
+#     that file.
+#
+# Run the create_Run3Scouting_test_file_cfg.py configuration and
+# rename the file it creates.
+#
+# The versions of the classes are encoded in the filenames in
+# alphabetical order. The only version that changed from 12_4_0
+# to 13_0_3 was the Run3ScoutingElectron class.
+#
+# 12_4_0 was chosen because the 12_4_X release cycle was used
+# for 2022 data, and the scouting data formats were not updated
+# after 12_4_0.
+#
+# 13_0_3 was chosen because the 13_0_X release cycle was used
+# for 2023 data, and the scouting data formats and ROOT were
+# not updated after 13_0_3.
+
+file=testRun3Scouting_v3_v5_v3_v4_v5_v3_v5_v3_v3_CMSSW_12_4_0.root
+inputfile=$(edmFileInPath DataFormats/Scouting/data/$file) || die "Failure edmFileInPath DataFormats/Scouting/data/$file" $?
+cmsRun ${LOCAL_TEST_DIR}/test_readRun3Scouting_CMSSW_12_4_0_cfg.py "$inputfile" || die "Failed to read old file $file" $?
+
+file=testRun3Scouting_v3_v6_v3_v4_v5_v3_v5_v3_v3_CMSSW_13_0_3.root
+inputfile=$(edmFileInPath DataFormats/Scouting/data/$file) || die "Failure edmFileInPath DataFormats/Scouting/data/$file" $?
+cmsRun ${LOCAL_TEST_DIR}/test_readRun3Scouting_cfg.py "$inputfile" || die "Failed to read old file $file" $?
+
+exit 0