Ensure VTKHDF outputs are closed on simulation failures

src/SPHCellList.jl

@@ -851,30 +851,39 @@ using TimerOutputs: @timeit
     function RunWithSimulationFinalizer!(RunFunction, SimMetaData, SimLogger, output)
         OutputFinalized = Ref(false)
 
+        function FinalizeOnce!(log_status::String)
+            if !OutputFinalized[]
+                FinalizeSimulationOutput!(SimMetaData, SimLogger, output; log_status=log_status)
+                OutputFinalized[] = true
+            end
+            return nothing
+        end
+
         atexit() do
             if !OutputFinalized[]
                 @warn "Julia is exiting before the simulation completed; closing VTKHDF output, finalizing the log, and opening ParaView for the data written so far."
-                FinalizeSimulationOutput!(SimMetaData, SimLogger, output; log_status="stopped as Julia exited")
-                OutputFinalized[] = true
+                FinalizeOnce!("stopped as Julia exited")
             end
         end
 
         Base.exit_on_sigint(false)
 
         # This is the smallest reliable Ctrl+C boundary for REPL/VS Code/terminal
         # execution: without catching `InterruptException`, Julia returns control
-        # to the caller and the `atexit` hook is not guaranteed to run.
+        # to the caller and the `atexit` hook is not guaranteed to run. The same
+        # boundary also closes VTKHDF files for ordinary simulation failures
+        # before rethrowing the original error to the caller.
         try
             RunFunction(OutputFinalized)
         catch e
             if e isa InterruptException
                 @warn "Simulation interrupted; closing VTKHDF output, finalizing the log, and opening ParaView for the data written so far."
-                if !OutputFinalized[]
-                    FinalizeSimulationOutput!(SimMetaData, SimLogger, output; log_status="interrupted")
-                    OutputFinalized[] = true
-                end
+                FinalizeOnce!("interrupted")
                 return nothing
             end
+
+            @warn "Simulation failed; closing VTKHDF output, finalizing the log, and opening ParaView for the data written so far." exception=(e, catch_backtrace())
+            FinalizeOnce!("failed")
             rethrow()
         end
 

test/runtests.jl

@@ -72,3 +72,26 @@ end
     @test particles.Velocity[1][1] == 0
     @test particles.Velocity[1][2] < 0
 end
+
+@testset "simulation failure finalizes output" begin
+    mktempdir() do dir
+        meta = SimulationMetaData{2,Float64}(
+            SimulationName="failfinalizer",
+            SaveLocation=dir,
+            VisualizeInParaview=false,
+            OpenLogFile=false,
+        )
+        logger = SimulationLogger(dir; to_console=false)
+        closed = Ref(false)
+        output = (
+            close_files = () -> (closed[] = true; nothing),
+            variable_names = String[],
+        )
+
+        @test_throws ErrorException SPHExample.SPHCellList.RunWithSimulationFinalizer!(meta, logger, output) do _
+            error("boom")
+        end
+        @test closed[]
+        close(logger.LoggerIo)
+    end
+end