Check that equivalent cells compile a form the same way

tests/tsfc/test_sum_factorisation.py

@@ -3,7 +3,7 @@
 
 from ufl import (Mesh, FunctionSpace, TestFunction, TrialFunction,
                  TensorProductCell, dx, action, interval, triangle,
-                 quadrilateral, curl, dot, div, grad)
+                 quadrilateral, hexahedron, curl, dot, div, grad)
 from finat.ufl import (FiniteElement, VectorElement, EnrichedElement,
                        TensorProductElement, HCurlElement, HDivElement)
 
@@ -190,6 +190,19 @@ def test_vector_laplace_action(cell, order):
     assert (rates < order).all()
 
 
+@pytest.mark.parametrize(('cell', 'equivalent_cell'),
+                         [(quadrilateral, TensorProductCell(interval, interval)),
+                          (hexahedron, TensorProductCell(quadrilateral, interval)),
+                          (hexahedron, TensorProductCell(interval, interval, interval))])
+@pytest.mark.parametrize('degree', [3, 5])
+def test_equivalent_cells(cell, equivalent_cell, degree):
+    """A form is compiled the same way on cells that hold the same space."""
+    a = helmholtz(cell, degree)
+    b = helmholtz(equivalent_cell, degree)
+    assert count_flops(a) == count_flops(b)
+    assert count_flops(action(a)) == count_flops(action(b))
+
+
 if __name__ == "__main__":
     import os
     import sys