"""Unit tests for the function library"""

# Copyright (C) 2011 Kristian B. Oelgaard
#
# This file is part of DOLFIN.
#
# DOLFIN is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# DOLFIN is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with DOLFIN. If not, see <http://www.gnu.org/licenses/>.
#
# First added:  2011-11-28
# Last changed: 2014-05-30

import unittest
from dolfin import *
import ufl
import dolfin

@unittest.skipIf(MPI.size(mpi_comm_world()) > 1, "Skipping unit test(s) not working in parallel")
class SpecialFunctions(unittest.TestCase):

    def testFacetArea(self):

        references = [(UnitIntervalMesh(1), 2, 2),\
                      (UnitSquareMesh(1,1), 4, 4),\
                      (UnitCubeMesh(1,1,1), 6, 3)]
        for mesh, surface, ref_int in references:
            c = Constant(1, mesh.ufl_cell()) # FIXME
            c0 = ufl.FacetArea(mesh)
            c1 = dolfin.FacetArea(mesh)
            self.assertAlmostEqual(assemble(c*dx(mesh)), 1)
            self.assertAlmostEqual(assemble(c*ds(mesh)), surface)
            self.assertAlmostEqual(assemble(c0*ds(mesh)), ref_int)
            self.assertAlmostEqual(assemble(c1*ds(mesh)), ref_int)

if __name__ == "__main__":
    unittest.main()