def test_edge_errors():
"""Edge input cases cause errors."""
@attr.s
class A(object):
pass
with pytest.raises(ValueError):
# Can't generate for only one class.
create_uniq_field_dis_func(A)
@attr.s
class B(object):
pass
with pytest.raises(ValueError):
# No fields on either class.
create_uniq_field_dis_func(A, B)
@attr.s
class C(object):
a = attr.ib()
@attr.s
class D(object):
a = attr.ib()
with pytest.raises(ValueError):
# No unique fields on either class.
create_uniq_field_dis_func(C, D)
def test_disambiguation(cl_and_vals_a, cl_and_vals_b):
"""Disambiguation should work when there are unique fields."""
cl_a, vals_a = cl_and_vals_a
cl_b, vals_b = cl_and_vals_b
req_a = {a.name for a in attr.fields(cl_a)}
req_b = {a.name for a in attr.fields(cl_b)}
assume(len(req_a))
assume(len(req_b))
assume((req_a - req_b) or (req_b - req_a))
fn = create_uniq_field_dis_func(cl_a, cl_b)
assert fn(attr.asdict(cl_a(*vals_a))) is cl_a
def test_fallback(cl_and_vals):
"""The fallback case works."""
cl, vals = cl_and_vals
assume(attr.fields(cl)) # At least one field.
@attr.s
class A(object):
pass
fn = create_uniq_field_dis_func(A, cl)
assert fn({}) is A
assert fn(attr.asdict(cl(*vals))) is cl
attr_names = {a.name for a in attr.fields(cl)}
if "xyz" not in attr_names:
fn({"xyz": 1}) is A # Uses the fallback.
def test_disambiguation(cl_and_vals_a, cl_and_vals_b):
"""Disambiguation should work when there are unique required fields."""
cl_a, vals_a = cl_and_vals_a
cl_b, vals_b = cl_and_vals_b
req_a = {a.name for a in attr.fields(cl_a)}
req_b = {a.name for a in attr.fields(cl_b)}
assume(len(req_a))
assume(len(req_b))
assume((req_a - req_b) or (req_b - req_a))
for attr_name in req_a - req_b:
assume(getattr(attr.fields(cl_a), attr_name).default is NOTHING)
for attr_name in req_b - req_a:
assume(getattr(attr.fields(cl_b), attr_name).default is NOTHING)
fn = create_uniq_field_dis_func(cl_a, cl_b)
assert fn(attr.asdict(cl_a(*vals_a))) is cl_a
