From 4c6a4e2c2ede4b11cf600e0e59f146fdcb7a0c53 Mon Sep 17 00:00:00 2001
From: "Joshua E. Hansel" <joshua.hansel@inl.gov>
Date: Tue, 15 Aug 2023 07:40:27 -0500
Subject: [PATCH] Threw error for post-processor/scalar output mismatch in CSV

Refs #25211
---
 framework/src/outputs/CSV.C  | 10 ++++++++++
 test/tests/outputs/csv/csv.i |  7 +++++--
 test/tests/outputs/csv/tests |  8 ++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/framework/src/outputs/CSV.C b/framework/src/outputs/CSV.C
index befa95b4ef4c..50c44e981faf 100644
--- a/framework/src/outputs/CSV.C
+++ b/framework/src/outputs/CSV.C
@@ -90,6 +90,16 @@ CSV::initialSetup()
       MooseUtils::clearSymlink(out_final);
     }
   }
+
+  // See https://github.com/idaholab/moose/issues/25211.
+  if ((advancedExecuteOn().find("postprocessors")->second !=
+           advancedExecuteOn().find("scalars")->second &&
+       getScalarOutput().size() > 0) ||
+      (advancedExecuteOn().find("postprocessors")->second !=
+           advancedExecuteOn().find("reporters")->second &&
+       getReporterOutput().size() > 0))
+    mooseError("The parameters 'execute_postprocessors_on', 'execute_scalars_on', and "
+               "'execute_reporters_on' must be the same for CSV output.");
 }
 
 std::string
diff --git a/test/tests/outputs/csv/csv.i b/test/tests/outputs/csv/csv.i
index b23fd294f780..b120f4c2758d 100644
--- a/test/tests/outputs/csv/csv.i
+++ b/test/tests/outputs/csv/csv.i
@@ -85,8 +85,11 @@
 []
 
 [Outputs]
-  execute_on = 'timestep_end'
-  csv = true
+  file_base = 'csv_out'
+  [csv]
+    type = CSV
+    execute_on = 'TIMESTEP_END'
+  []
 []
 
 [ICs]
diff --git a/test/tests/outputs/csv/tests b/test/tests/outputs/csv/tests
index 13b50ce3d460..7521720557ea 100644
--- a/test/tests/outputs/csv/tests
+++ b/test/tests/outputs/csv/tests
@@ -105,4 +105,12 @@
     requirement = "The system shall support CSV output to files on nonlinear iterations, generating unique filenames containing the time step and current nonlinear iteration number."
     issues = "#24705"
   []
+  [pp_scalar_execute_on_mismatch]
+    type = RunException
+    input = 'csv.i'
+    cli_args = 'Outputs/csv/execute_postprocessors_on=FINAL'
+    expect_err = "The parameters 'execute_postprocessors_on', 'execute_scalars_on', and 'execute_reporters_on' must be the same for CSV output"
+    requirement = "The system shall report an error if post-processors and scalar variables have different output frequency."
+    issues = "#25211"
+  []
 []