Add test for vtk writing

test/forest/test_write_vtk.jl

@@ -0,0 +1,41 @@
+# This file tests the writing of data to vtk files.
+# All t8code eclasses are tested with a basic forest with elements of level 0 to 3.
+@testset "test_write_vtk" begin
+    outdir = "out_test"
+    mkdir(outdir)
+    for eclass in T8_ECLASS_ZERO:t8_eclass(T8_ECLASS_COUNT - 1)
+        for level in 0:3
+            scheme = t8_scheme_new_default_cxx()
+            cmesh = t8_cmesh_new_hypercube(t8_eclass(eclass), comm, 0, 0, 0)
+            forest = t8_forest_new_uniform(cmesh, scheme, level, 0, comm)
+
+            num_elements = t8_forest_get_local_num_elements(forest)
+
+            data = rand(num_elements)
+
+            vtk_data = t8_vtk_data_field_t(T8_VTK_SCALAR,
+                                           NTuple{8192, Cchar}(rpad("data_1)\0", 8192, ' ')),
+                                           pointer(data))
+
+            # The number of user defined data fields to write.
+            num_data = 1
+
+            # Write user defined data to vtu file.
+            write_treeid = 1
+            write_mpirank = 1
+            write_level = 1
+            write_element_id = 1
+            write_ghosts = 0
+            file = joinpath(outdir, "data_" * string(eclass) * "_" * string(level))
+            t8_forest_write_vtk_ext(forest, file, write_treeid, write_mpirank,
+                                    write_level, write_element_id, write_ghosts,
+                                    0, 0, num_data, Ref(vtk_data))
+
+            @test isfile(file * "_0000.vtu") && isfile(file * ".pvtu")
+
+            t8_forest_unref(Ref(forest))
+        end
+    end
+
+    rm(outdir, recursive = true)
+end

test/test_all.jl

@@ -33,6 +33,7 @@ end
 
 @testset "forest" begin
     include("forest/test_element_volume.jl")
+    include("forest/test_write_vtk.jl")
 end
 
 end # module