[test.vtk] adds checking of written vtk files

via calling paraview's python bindings if available
this refs #284

src/pymor/tools/vtkio.py

@@ -68,6 +68,7 @@ def _write_vtu_series(grid, coordinates, connectivity, data, filename_base, last
         w.save()
         group.addFile(filepath=fn, sim_time=i)
     group.save()
+    return (fn_tpl.format(filename_base, i) for i in range(steps))
 
 def write_vtk(grid, data, filename_base, codim=2, binary_vtk=True, last_step=None):
     """Output grid-associated data in (legacy) vtk format
@@ -86,6 +87,8 @@ def write_vtk(grid, data, filename_base, codim=2, binary_vtk=True, last_step=Non
 
     last_step
         if set must be <= len(data) to restrict output of timeseries
+
+    :return list of filenames written
     """
     if not config.HAVE_PYVTK:
         raise ImportError('could not import pyevtk')
@@ -96,6 +99,6 @@ def write_vtk(grid, data, filename_base, codim=2, binary_vtk=True, last_step=Non
 
     subentities, coordinates, entity_map = flatten_grid(grid)
     x, y, z = coordinates[:, 0].copy(), coordinates[:, 1].copy(), np.zeros(coordinates[:, 1].size)
-    _write_vtu_series(grid, coordinates=(x, y, z), connectivity=subentities, data=data.data,
+    return _write_vtu_series(grid, coordinates=(x, y, z), connectivity=subentities, data=data.data,
                       filename_base=filename_base, last_step=last_step, is_cell_data=(codim == 0))
 

src/pymortests/fixtures/grid.py

@@ -86,10 +86,18 @@ def subgrid_factory(grid_generator, neq, seed):
 def grid(request):
     return request.param()
 
+@pytest.fixture(params=rect_grid_generators)
+def rect_grid(request):
+    return request.param()
+
 @pytest.fixture(params=(rect_grid_generators + tria_grid_generators))
 def rect_or_tria_grid(request):
     return request.param()
 
+@pytest.fixture(params=tria_grid_generators)
+def tria_grid(request):
+    return request.param()
+
 @pytest.fixture(params=(rect_grid_generators + oned_grid_generators))
 def grid_with_orthogonal_centers(request):
     return request.param()

src/pymortests/paraview_file_check.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python2
+
+if __name__ == '__main__':
+    import sys
+
+    try:
+        import paraview.simple as ps
+    except ImportError:
+        sys.exit(77)
+
+    reader = ps.OpenDataFile(sys.argv[1])
+    ps.Show()

src/pymortests/tools.py

@@ -8,8 +8,10 @@
 import itertools
 from tempfile import NamedTemporaryFile
 
+import subprocess
+
 from pymortests.base import TestInterface, runmodule
-from pymortests.fixtures.grid import rect_or_tria_grid
+from pymortests.fixtures.grid import rect_or_tria_grid, rect_grid, tria_grid
 from pymortests.base import polynomials
 from pymor.tools.deprecated import Deprecated
 from pymor.tools.quadratures import GaussQuadratures
@@ -85,17 +87,29 @@ def test_props(self):
                 assert not float_cmp(-inf, inf, rtol, atol), msg
 
 
+def _check_vtk_file(path):
+    try:
+        # this check will current fail if no python2 is available
+        # it needs to be a seperate process since there are no py3 bindings for paraview
+        out = subprocess.check_output(['./paraview_file_check.py', path], stderr=subprocess.STDOUT, universal_newlines=False)
+    except subprocess.CalledProcessError as cpe:
+        assert cpe.returncode == 77  #no paraview bindings, special hardcoded magic value :|
+    else:
+        # paraview bindings to not raise an Exception for unreadable files. (Or ANY unrecoverable error afaict)
+        assert 'Error' not in out
+
 def test_vtkio(rect_or_tria_grid):
     grid = rect_or_tria_grid
-    steps = 4
-    for dim in range(1, 2):
-        for codim, data in enumerate((NumpyVectorSpace.from_data(np.zeros((steps, grid.size(c)))) for c in range(grid.dim+1))):
-            with NamedTemporaryFile('wb') as out:
-                if codim == 1:
-                    with pytest.raises(NotImplementedError):
-                        write_vtk(grid, data, out.name, codim=codim)
-                else:
+    steps = 1
+    for codim, data in enumerate((NumpyVectorSpace.from_data(np.zeros((steps, grid.size(c)))) for c in range(grid.dim+1))):
+        with NamedTemporaryFile('wb', delete=False) as out:
+            if codim == 1:
+                with pytest.raises(NotImplementedError):
                     write_vtk(grid, data, out.name, codim=codim)
+            else:
+                files = write_vtk(grid, data, out.name, codim=codim)
+                for f in files:
+                    _check_vtk_file(f)
 
 
 class TestTiming(TestInterface):