test compile_expression_dual_evaluation with symbolics

Tests for non-dependence of compile_expression_dual_evaluation on
numerics by checking it works with purely symbolic expressions.

Author: ReubenHill

tests/test_dual_evaluation.py

@@ -0,0 +1,57 @@
+import pytest
+import ufl
+from tsfc.finatinterface import create_element
+from tsfc import compile_expression_dual_evaluation
+
+
+def test_ufl_only_simple():
+    mesh = ufl.Mesh(ufl.VectorElement("P", ufl.triangle, 1))
+    V = ufl.FunctionSpace(mesh, ufl.FiniteElement("P", ufl.triangle, 2))
+    v = ufl.Coefficient(V)
+    expr = ufl.inner(v, v)
+    W = V
+    to_element = create_element(W.ufl_element())
+    ast, oriented, needs_cell_sizes, coefficients, _ = compile_expression_dual_evaluation(expr, to_element, coffee=False)
+
+
+def test_ufl_only_spatialcoordinate():
+    mesh = ufl.Mesh(ufl.VectorElement("P", ufl.triangle, 1))
+    V = ufl.FunctionSpace(mesh, ufl.FiniteElement("P", ufl.triangle, 2))
+    x, y = ufl.SpatialCoordinate(mesh)
+    expr = x*y - y**2 + x
+    W = V
+    to_element = create_element(W.ufl_element())
+    ast, oriented, needs_cell_sizes, coefficients, _ = compile_expression_dual_evaluation(expr, to_element, coffee=False)
+
+
+def test_ufl_only_from_contravariant_piola():
+    mesh = ufl.Mesh(ufl.VectorElement("P", ufl.triangle, 1))
+    V = ufl.FunctionSpace(mesh, ufl.FiniteElement("RT", ufl.triangle, 1))
+    v = ufl.Coefficient(V)
+    expr = ufl.inner(v, v)
+    W = ufl.FunctionSpace(mesh, ufl.FiniteElement("P", ufl.triangle, 2))
+    to_element = create_element(W.ufl_element())
+    ast, oriented, needs_cell_sizes, coefficients, _ = compile_expression_dual_evaluation(expr, to_element, coffee=False)
+
+
+def test_ufl_only_to_contravariant_piola():
+    mesh = ufl.Mesh(ufl.VectorElement("P", ufl.triangle, 1))
+    V = ufl.FunctionSpace(mesh, ufl.FiniteElement("P", ufl.triangle, 2))
+    v = ufl.Coefficient(V)
+    expr = ufl.as_vector([v, v])
+    W = ufl.FunctionSpace(mesh, ufl.FiniteElement("RT", ufl.triangle, 1))
+    to_element = create_element(W.ufl_element())
+    ast, oriented, needs_cell_sizes, coefficients, _ = compile_expression_dual_evaluation(expr, to_element, coffee=False)
+
+
+def test_ufl_only_shape_mismatch():
+    mesh = ufl.Mesh(ufl.VectorElement("P", ufl.triangle, 1))
+    V = ufl.FunctionSpace(mesh, ufl.FiniteElement("RT", ufl.triangle, 1))
+    v = ufl.Coefficient(V)
+    expr = ufl.inner(v, v)
+    assert expr.ufl_shape == ()
+    W = V
+    to_element = create_element(W.ufl_element())
+    assert to_element.value_shape == (2,)
+    with pytest.raises(ValueError):
+        ast, oriented, needs_cell_sizes, coefficients, _ = compile_expression_dual_evaluation(expr, to_element, coffee=False)