How to use punq - 10 common examples

def test_registering_a_callable_as_concrete_is_exception():
    """
    Likewise, if we register an arbitrary callable, there's
    no key by which we can later resolve, so we reject the
    registration
    """

    container = Container()

    with pytest.raises(InvalidRegistrationException):
        container.register(lambda: "oops")

def test_can_register_an_instance():
    container = Container()
    writer = TmpFileMessageWriter("my-file")
    container.register(MessageWriter, instance=writer)
    expect(container.resolve(MessageWriter)).to(equal(writer))

def test_forward_references_can_be_registered_as_strings():
    """
    For cases where you want to declare a ref like 'module.Dep' we allow you to
    resolve a forward reference with an arbitrary string.
    """
    container = punq.Container()
    container.register("Dependency", DataAccessLayer)
    container.register(Client)

    instance = container.resolve(Client)
    assert instance.dep.val == 2

def test_defaults_are_superseded_by_context():
    container = Container()
    container.register(Dep)
    container.register(Client)

    client = container.resolve(Client, b=5)
    expect(client.b).to(equal(5))

def test_resolve_all_returns_all_registrations_in_order():
    container = Container()
    container.register(MessageWriter, StdoutMessageWriter)
    container.register(MessageWriter, TmpFileMessageWriter, path="my-file")

    [first, second] = container.resolve_all(MessageWriter)
    expect(first).to(be_a(StdoutMessageWriter))
    expect(second).to(be_a(TmpFileMessageWriter))

def test_can_resolve_objects_with_forward_references():
    """
    If we've already registered a type with the name 'Dependency' then we
    should be able to resolve the forward reference.
    """
    container = punq.Container()
    container.register(Dependency)
    container.register(Client)

    instance = container.resolve(Client)
    assert instance.dep.val == 1

def test_can_provide_arguments_to_resolve():
    container = Container()
    container.register(MessageWriter, TmpFileMessageWriter)

    instance = container.resolve(MessageWriter, path="foo")
    expect(instance.path).to(equal("foo"))

def test_resolves_instances_with_prototype_scope():
    container = Container()
    container.register(MessageWriter, StdoutMessageWriter, scope=Scope.transient)

    mw1 = container.resolve(MessageWriter)
    mw2 = container.resolve(MessageWriter)
    expect(mw1).not_to(equal(mw2))

def test_can_register_with_a_custom_factory():
    container = Container()
    container.register(MessageWriter, lambda: "win")
    container.register(MessageSpeaker, HelloWorldSpeaker)

    speaker = container.resolve(MessageSpeaker)

    expect(speaker).to(be_a(HelloWorldSpeaker))
    expect(speaker.writer).to(equal("win"))

def test_can_register_a_concrete_type():
    container = Container()
    container.register(StdoutMessageWriter)

    expect(container.resolve(StdoutMessageWriter)).to(be_a(StdoutMessageWriter))