def test_unknown(self, C):
"""
Wanting to change an unknown attribute raises a ValueError.
"""
# No generated class will have a four letter attribute.
with pytest.raises(AttrsAttributeNotFoundError) as e:
assoc(C(), aaaa=2)
assert (
"aaaa is not an attrs attribute on {cls!r}.".format(cls=C),
) == e.value.args
def test_unknown(self, C):
"""
Wanting to change an unknown attribute raises a ValueError.
"""
@attributes
class C(object):
x = attr()
y = 42
with pytest.raises(ValueError) as e:
assoc(C(1), y=2)
assert ("y is not an attrs attribute on {cl!r}.".format(cl=C),) == e.value.args
def test_unknown(self):
"""
Wanting to change an unknown attribute raises a ValueError.
"""
@attributes
class C(object):
x = attr()
y = 42
with pytest.raises(ValueError) as e:
assoc(C(1), y=2)
assert ("y is not an attrs attribute on {cl!r}.".format(
cl=C), ) == e.value.args
def test_no_changes(self, C):
"""
No changes means a verbatim copy.
"""
i1 = C(1, 2)
i2 = assoc(i1)
assert i1 is not i2
assert i1 == i2
def test_no_changes(self, C):
"""
No changes means a verbatim copy.
"""
i1 = C()
i2 = assoc(i1)
assert i1 is not i2
assert i1 == i2
def test_frozen(self):
"""
Works on frozen classes.
"""
@attributes(frozen=True)
class C(object):
x = attr()
y = attr()
assert C(3, 2) == assoc(C(1, 2), x=3)
def test_change(self, C, val):
"""
Changes work.
"""
# Take the first attribute, and change it.
assume(fields(C)) # Skip classes with no attributes.
original = C()
attribute = fields(C)[0]
changed = assoc(original, **{attribute.name: val})
assert getattr(changed, attribute.name) == val
def test_empty(self):
"""
Empty classes without changes get copied.
"""
@attributes
class C(object):
pass
i1 = C()
i2 = assoc(i1)
assert i1 is not i2
assert i1 == i2
def test_empty(self, slots, frozen):
"""
Empty classes without changes get copied.
"""
@attributes(slots=slots, frozen=frozen)
class C(object):
pass
i1 = C()
i2 = assoc(i1)
assert i1 is not i2
assert i1 == i2
def test_empty(self):
"""
Empty classes without changes get copied.
"""
@attributes
class C(object):
pass
i1 = C()
i2 = assoc(i1)
assert i1 is not i2
assert i1 == i2
def test_change(self, C, data):
"""
Changes work.
"""
# Take the first attribute, and change it.
assume(fields(C)) # Skip classes with no attributes.
field_names = [a.name for a in fields(C)]
original = C()
chosen_names = data.draw(st.sets(st.sampled_from(field_names)))
change_dict = {name: data.draw(st.integers())
for name in chosen_names}
changed = assoc(original, **change_dict)
for k, v in change_dict.items():
assert getattr(changed, k) == v
def test_change(self, C):
"""
Changes work.
"""
i = assoc(C(1, 2), x=42)
assert C(42, 2) == i
def test_change(self, C):
"""
Changes work.
"""
i = assoc(C(1, 2), x=42)
assert C(42, 2) == i
