def test_can_override_handlers_for_supertypes():
s = SpecificationMapper()
s.define_specification_for_instances(tuple, lambda s, d: sum(d))
s.define_specification_for_instances(Litter, lambda s, d: len(d))
assert s.specification_for((1, 2)) == 3
assert s.specification_for(Litter(2, 2)) == 2
def test_can_define_class_specifications_for_subclasses():
s = SpecificationMapper()
s.define_specification_for_classes(const(1))
s.define_specification_for_classes(const(2), subclasses_of=Foo)
assert s.specification_for(Foo) == 2
assert s.specification_for(Fooc) == 2
assert s.specification_for(Baz) == 1
def test_defining_new_handlers_resets_cache():
s = SpecificationMapper()
s.define_specification_for_instances(str, lambda *_: Foo())
x = s.specification_for('foo')
s.define_specification_for_instances(str, lambda *_: Fooc())
y = s.specification_for('foo')
assert y is not x
assert isinstance(y, Fooc)
def test_can_call_previous_in_overridden_specifications():
s = SpecificationMapper()
s.define_specification_for_instances(str, lambda _, s: len(s))
s.define_specification_for_instances(
str, lambda _, s: 5 if len(s) > 5 else next_in_chain())
assert s.specification_for('foo') == 3
assert s.specification_for(
'I am the very model of a modern major general') == 5
def test_can_override_in_children():
sm = SpecificationMapper()
child = sm.new_child_mapper()
sm.define_specification_for('foo', const(1))
child.define_specification_for('foo', const(2))
assert sm.specification_for('foo') == 1
assert child.specification_for('foo') == 2
def test_is_not_confused_by_equal_things_of_different_types():
mapper = SpecificationMapper()
mapper.define_specification_for_instances(Confused1, lambda s, d: 1)
mapper.define_specification_for_instances(Confused2, lambda s, d: 2)
mapper.define_specification_for_instances(
tuple, lambda s, d: sum(s.specification_for(x) for x in d))
assert mapper.specification_for((Confused1(), )) == 1
assert mapper.specification_for((Confused2(), )) == 2
def test_cache_correctly_handles_inheritance():
s = SpecificationMapper()
s.define_specification_for_instances(
list, lambda s, d: [s.specification_for(d[0])])
t = s.new_child_mapper()
t.define_specification_for_instances(str, lambda *_: Foo())
x = t.specification_for('foo')
y = t.specification_for(['foo'])[0]
assert x is y
def test_can_handle_large_numbers_of_instance_mappers():
def f(s, x):
return str(x)
s = SpecificationMapper()
s.define_specification_for_instances(tuple, f)
s.define_specification_for_instances(Litter, f)
s.define_specification_for_instances(list, f)
s.define_specification_for_instances(set, f)
s.define_specification_for_instances(str, f)
s.define_specification_for_instances(int, f)
assert s.specification_for((1, 1)) == '(1, 1)'
def test_chooses_most_specific_subclass(classes, r):
classes = list(classes)
random.shuffle(classes)
classes = tuple(classes)
mapper = SpecificationMapper()
for i in hrange(len(classes)):
mapper.define_specification_for_instances(
classes[i],
const(i),
)
for c in all_test_classes:
if issubclass(c, classes):
x = c()
correct_choice = find_most_specific(x, classes)
i = mapper.specification_for(x)
assert i == classes.index(correct_choice)
def test_can_define_instance_specifications_for_lists():
sm = SpecificationMapper()
sm.define_specification_for_instances(list, lambda _, l: len(l))
assert sm.specification_for([1, 2]) == 2
def test_can_define_instance_specifications_on_the_default():
sm = SpecificationMapper()
SpecificationMapper.default().define_specification_for_instances(
str, lambda _, i: i + 'bar')
assert sm.specification_for('foo') == 'foobar'
def test_can_define_specifications_for_built_in_types():
sm = SpecificationMapper()
sm.define_specification_for(Bar, const(1))
assert sm.specification_for(Bar) == 1
def test_can_define_class_specifications():
s = SpecificationMapper()
s.define_specification_for_classes(lambda _, c: c())
assert s.specification_for(Foo).__class__ == Foo
def test_specifications_will_match_on_subclasses():
s = SpecificationMapper()
def trivial(x):
return lambda s, d: x
s.define_specification_for_instances(Parent, trivial(1))
assert s.specification_for(Parent()) == 1
assert s.specification_for(Child()) == 1
assert s.specification_for(Grandchild()) == 1
assert s.specification_for(GreatGrandchild()) == 1
s.define_specification_for_instances(Grandchild, trivial(2))
assert s.specification_for(Parent()) == 1
assert s.specification_for(Child()) == 1
assert s.specification_for(Grandchild()) == 2
assert s.specification_for(GreatGrandchild()) == 2
s.define_specification_for_instances(Child, trivial(3))
assert s.specification_for(Parent()) == 1
assert s.specification_for(Child()) == 3
assert s.specification_for(Grandchild()) == 2
assert s.specification_for(GreatGrandchild()) == 2
s.define_specification_for_instances(GreatGrandchild, trivial(4))
assert s.specification_for(Parent()) == 1
assert s.specification_for(Child()) == 3
assert s.specification_for(Grandchild()) == 2
assert s.specification_for(GreatGrandchild()) == 4
choices = [Parent, Child, Grandchild, GreatGrandchild]
values = {Parent: 1, Child: 3, Grandchild: 2, GreatGrandchild: 4}
for i in hrange(5, 200):
c = random.choice(choices)
assert s.specification_for(c()) == values[c]
s.define_specification_for_instances(c, trivial(i))
assert s.specification_for(c()) == i
values[c] = i
def test_can_define_specifications_on_the_default():
sm = SpecificationMapper()
SpecificationMapper.default().define_specification_for('foo', const(1))
assert sm.specification_for('foo') == 1
def test_invokes_missing_if_all_handlers_defer():
s = SpecificationMapper()
s.define_specification_for(int, lambda ss, d: next_in_chain())
s.missing_specification = lambda d: 11
assert s.specification_for(int) == 11
def test_can_override_instance_specifications():
s = SpecificationMapper()
s.define_specification_for_instances(str, const(1))
s.define_specification_for_instances(str, const(2))
assert s.specification_for('foo') == 2
def test_raises_missing_specification_with_no_spec():
sm = SpecificationMapper()
with pytest.raises(MissingSpecification):
sm.specification_for('hi')
def test_multiple_calls_return_same_value():
s = SpecificationMapper()
s.define_specification_for_instances(str, lambda *_: Foo())
assert s.specification_for('foo') is s.specification_for('foo')
assert s.specification_for('foo') is not s.specification_for('bar')
def test_can_handle_subtypes_of_instances():
s = SpecificationMapper()
s.define_specification_for_instances(tuple, lambda s, d: sum(d))
assert s.specification_for((1, 2)) == 3
assert s.specification_for(Litter(2, 2)) == 4
def test_can_define_specifications():
sm = SpecificationMapper()
sm.define_specification_for('foo', const(1))
assert sm.specification_for('foo') == 1
def test_can_call_other_specs():
s = SpecificationMapper()
s.define_specification_for('foo', const(1))
s.define_specification_for('bar',
lambda t, _: t.specification_for('foo') + 1)
assert s.specification_for('bar') == 2