more tests now pass + check for error

Author: RemDelaporteMathurin

test/test_vtx.py

@@ -269,10 +269,9 @@ def test_custom_field(tmp_path, expression):
         lambda T: T + 1,
         lambda c_A, c_B: c_A + c_B,
         lambda c_A, T: c_A * T,
-        # FIXME: the following don't work (easily) because of https://github.com/FEniCS/dolfinx/issues/3207
-        # lambda c_A, c_B, x: c_A * c_B + x[0],
-        # lambda c_A, T, x: c_A * T + x[0],
-        # lambda T, x: T + x[0],
+        lambda c_A, c_B, x: c_A * c_B + x[0],
+        lambda c_A, T, x: c_A * T + x[0],
+        lambda T, x: T + x[0],
     ],
 )
 def test_custom_field_discontinuous(tmp_path, expression):
@@ -340,3 +339,67 @@ def test_custom_field_discontinuous(tmp_path, expression):
     my_model.initialise()
 
     my_model.run()
+
+
+@pytest.mark.parametrize(
+    "expression",
+    [lambda c_A, t: c_A * t, lambda t: t],
+)
+def test_custom_field_not_implemented_error(expression):
+    my_model = F.HydrogenTransportProblemDiscontinuous()
+
+    mat = F.Material(D_0=1, E_D=0, K_S_0=1, E_K_S=0)
+
+    vol = F.VolumeSubdomain(id=1, material=mat)
+
+    top = F.SurfaceSubdomain(id=1, locator=lambda x: np.isclose(x[1], 1))
+    bottom = F.SurfaceSubdomain(id=2, locator=lambda x: np.isclose(x[1], 0))
+    left = F.SurfaceSubdomain(id=3, locator=lambda x: np.isclose(x[0], 0))
+    right = F.SurfaceSubdomain(id=4, locator=lambda x: np.isclose(x[0], 1))
+
+    my_model.subdomains = [vol, top, bottom, left, right]
+
+    my_model.surface_to_volume = {top: vol, bottom: vol, left: vol, right: vol}
+
+    dolfinx_mesh = dolfinx.mesh.create_unit_square(MPI.COMM_WORLD, 10, 10)
+    my_model.mesh = F.Mesh(dolfinx_mesh)
+
+    A = F.Species("A", subdomains=my_model.volume_subdomains)
+    B = F.Species("B", subdomains=my_model.volume_subdomains)
+    C = F.Species("C", subdomains=my_model.volume_subdomains)
+    D = F.Species("D", subdomains=my_model.volume_subdomains)
+
+    my_model.species = [A, B, C, D]
+
+    my_model.boundary_conditions = (
+        [
+            F.FixedConcentrationBC(species=A, subdomain=top, value=1),
+            F.FixedConcentrationBC(species=B, subdomain=left, value=1),
+        ]
+        + [
+            F.FixedConcentrationBC(species=C, subdomain=surf, value=0)
+            for surf in [top, bottom, left, right]
+        ]
+        + [
+            F.FixedConcentrationBC(species=D, subdomain=surf, value=0)
+            for surf in [top, bottom, left, right]
+        ]
+    )
+
+    my_model.temperature = lambda x: 300 + 100 * x[0]
+
+    my_model.settings = F.Settings(transient=False, atol=1e-9, rtol=1e-9)
+
+    custom_field = F.CustomField(
+        filename="custom_field.bp",
+        expression=expression,
+        species_dependent_value={"c_A": A, "c_B": B},
+        subdomain=vol,
+    )
+
+    my_model.exports = [
+        custom_field,
+    ]
+
+    with pytest.raises(NotImplementedError):
+        my_model.initialise()