def test_bind_name_to_instance():
apple = Apple()
bindings = Bindings()
bindings.bind("apple").to_instance(apple)
injector = Injector(bindings)
assert injector.get("apple") is apple
def test_bind_type_to_provider():
apple = Apple()
bindings = Bindings()
bindings.bind(Apple).to_provider(lambda injector: apple)
injector = Injector(bindings)
assert injector.get(Apple) is apple
def test_can_bind_to_names():
apple_to_inject = Apple()
bindings = Bindings()
bindings.bind("apple").to_instance(apple_to_inject)
bindings.bind("another_apple").to_key("apple")
injector = Injector(bindings)
assert injector.get("another_apple") is apple_to_inject
def test_classes_that_inherit_from_injectable_have_members_injected():
class Foo(Base):
_tag_fetcher = dependency("tag_fetcher")
tag_fetcher = {'some': 'object'}
bindings = Bindings()
bindings.bind("tag_fetcher").to_instance(tag_fetcher)
injector = Injector(bindings)
assert injector.get(Foo)._tag_fetcher is tag_fetcher
def test_scoped_injectables_cannot_depend_on_injectables_in_separate_scope():
Name = zuice.key("Name")
class Greeter(zuice.Base):
_name = zuice.dependency(Name)
bindings = Bindings()
bindings.bind(Greeter).singleton()
injector = Injector(bindings)
error = assert_raises(NoSuchBindingException, lambda: injector.get(Greeter, {Name: "Bob"}))
def test_get_raises_exception_if_no_such_binding_exists():
injector = Injector(Bindings())
assert_raises(NoSuchBindingException, lambda: injector.get("apple"))
apple = Apple()
bindings = Bindings()
bindings.bind("apple").to_provider(lambda injector: apple)
injector = Injector(bindings)
assert injector.get("apple") is apple
assert_raises(NoSuchBindingException, lambda: injector.get("banana"))
def test_original_bindings_are_prefered_to_zero_arg_constructors():
class Unit(object):
pass
unit = Unit()
bindings = Bindings()
bindings.bind(Unit).to_instance(unit)
injector = Injector(bindings)
assert injector.get(Unit, {zuice.key("a"): "a"}) is unit
def test_cached_singleton_is_available_from_non_singleton_scope(self):
x = [0]
class Counter(object):
def __init__(self):
self.x = x[0] = x[0] + 1
bindings = Bindings()
bindings.bind(Counter).singleton()
injector = Injector(bindings)
assert_equal(1, injector.get(Counter, {"name": "Bob"}).x)
assert_equal(1, injector.get(Counter, {"name": "Jim"}).x)
def test_bindings_can_change_lifetime_to_singleton(self):
x = [0]
class Counter(object):
def __init__(self):
self.x = x[0] = x[0] + 1
bindings = Bindings()
bindings.bind(Counter).singleton()
injector = Injector(bindings)
assert_equal(1, injector.get(Counter).x)
assert_equal(1, injector.get(Counter).x)
def test_bindings_can_change_lifetime_of_provider_to_singleton(self):
x = [0]
def count(injector):
x[0] += 1
return x[0]
counter = zuice.key("counter")
bindings = Bindings()
bindings.bind(counter).to_provider(count).singleton()
injector = Injector(bindings)
assert_equal(1, injector.get(counter))
assert_equal(1, injector.get(counter))
def test_subclassing_injectable_objects_allows_injected_attributes_to_be_overwritten():
class Parent(Base):
_fetcher = dependency('tag_fetcher')
class Child(Parent):
_fetcher = dependency('post_fetcher')
post_fetcher = {'another': 'object'}
bindings = Bindings()
bindings.bind("post_fetcher").to_instance(post_fetcher)
injector = Injector(bindings)
child = injector.get(Child)
assert child._fetcher is post_fetcher
def test_unscoped_injectables_are_available_in_any_scope():
Greeting = zuice.key("Greeting")
Name = zuice.key("Name")
class Greeter(zuice.Base):
_greeting = zuice.dependency(Greeting)
_name = zuice.dependency(Name)
def hello(self):
return "{0} {1}".format(self._greeting, self._name)
bindings = Bindings()
bindings.bind(Greeting).to_instance("Hello")
injector = Injector(bindings)
greeter = injector.get(Greeter, {Name: "Bob"})
assert greeter.hello() == "Hello Bob"
def test_injectable_injects_attributes_of_sub_classes():
class Parent(Base):
_tag_fetcher = dependency('tag_fetcher')
class Child(Parent):
_blog_post_fetcher = dependency('post_fetcher')
tag_fetcher = {'some': 'object'}
post_fetcher = {'another': 'object'}
bindings = Bindings()
bindings.bind("tag_fetcher").to_instance(tag_fetcher)
bindings.bind("post_fetcher").to_instance(post_fetcher)
injector = Injector(bindings)
child = injector.get(Child)
assert child._tag_fetcher is tag_fetcher
assert child._blog_post_fetcher is post_fetcher
def test_changing_bindings_after_creating_injector_does_not_change_injector():
bindings = Bindings()
injector = Injector(bindings)
bindings.bind("apple").to_instance(Apple())
assert_raises(NoSuchBindingException, lambda: injector.get("apple"))