def __init__(self):
super(Domain, self).__init__()
self._service_map = service_map = self._instantiate_and_map_services()
# replace 'meta' with a variant for the instance (don't share self.__class__.meta)
self.meta = self.__class__.meta.get_instance_metadata(
service_map=service_map)
# replace 'deps' with a ShadowPortArray which serves as proxy to the deps of internal services
components = service_map.values()
component_deps = [
c.deps for c in components
if isinstance(getattr(c, 'deps', None), (PortArray,
ShadowPortArray))
]
discovered = AutoDiscoverConnections(components=components)
self.deps = ShadowPortArray(arrays=component_deps,
ignore_ports=discovered.satisfied_needs())
# materialize connections between services
wire_up_discovered_connections(discovered=discovered)
def test_SelfReferencingMadness_raised_if_component_attempts_to_satisfy_itself(
self):
class Mad(Service):
"""This isn't strictly speaking wrong, but cannot sensible participate in auto-wiring."""
deps = Needs('attention')
@provides
def attention(self):
return self.deps.attention()
with self.assertRaisesRegexp(
SelfReferencingMadness,
'.* both needs and provides "attention".*'):
AutoDiscoverConnections([Mad()])
def test_discovery_of_ports_from_a_collection_of_components_classes(self):
# We need to be able to discover connects between uninstantiated components for visualisation and analysis
A, B, C = self.get_services()
discovered = AutoDiscoverConnections([A, B, C])
self.assertEqual(['b1', 'c1', 'x', 'y'], discovered.get_needs())
self.assertEqual(['a1', 'b1', 'b2', 'c1'], discovered.get_provides())
self.assertEqual(['x', 'y'], discovered.unsatisfied_needs())
self.assertItemsEqual([
DiscoveredConnection(port_name='b1', consumer=A, provider=B),
DiscoveredConnection(port_name='c1', consumer=B, provider=C)
], discovered.connections())
self.assertEqual(A, discovered.get_provider('a1'))
self.assertEqual(B, discovered.get_provider('b1'))
self.assertEqual(B, discovered.get_provider('b2'))
self.assertEqual(C, discovered.get_provider('c1'))
with self.assertRaisesRegexp(UnknownPort, '"x1" is not a valid port'):
self.assertEqual(C, discovered.get_provider('x1'))
def test_discovery_when_there_are_no_ports(self):
class Empty(Service):
pass
empty_component = Empty()
discovered = AutoDiscoverConnections([empty_component])
self.assertEqual([], discovered.get_needs())
self.assertEqual([], discovered.get_provides())
self.assertEqual([], discovered.unsatisfied_needs())
self.assertEqual([], list(discovered.connections()))
def test_discovery_of_ports_from_a_collection_of_components_instances(
self):
A, B, C = self.get_services()
a = A()
b = B()
c = C()
discovered = AutoDiscoverConnections([a, b, c])
self.assertEqual(['b1', 'c1', 'x', 'y'], discovered.get_needs())
self.assertEqual(['a1', 'b1', 'b2', 'c1'], discovered.get_provides())
self.assertEqual(['x', 'y'], discovered.unsatisfied_needs())
self.assertItemsEqual([
DiscoveredConnection(port_name='b1', consumer=a, provider=b),
DiscoveredConnection(port_name='c1', consumer=b, provider=c)
], discovered.connections())
self.assertEqual(a, discovered.get_provider('a1'))
self.assertEqual(b, discovered.get_provider('b1'))
self.assertEqual(b, discovered.get_provider('b2'))
self.assertEqual(c, discovered.get_provider('c1'))
with self.assertRaisesRegexp(UnknownPort, '"x1" is not a valid port'):
self.assertEqual(c, discovered.get_provider('x1'))
def test_DuplicateProviders_raised_when_more_than_one_component_provides_the_same_port(
self):
class X(Service):
@provides
def x(self):
return 'X'
@provides
def y(self):
return 'Y'
class Axe(Service):
@provides
def x(self):
return 'X'
with self.assertRaisesRegexp(DuplicateProviders,
'Duplicate providers for "x".*'):
AutoDiscoverConnections([X(), Axe()])
def __new__(mcs, name, bases, state):
if bases == (
INeed,
IProvide): # This is the Domain class itself, not its subclass
return type.__new__(mcs, name, bases, state)
mcs.validate_overridden_attributes(attrs=state, class_name=name)
if '__services__' not in state or not isinstance(
state['__services__'], (list, tuple)):
raise DomainDefinitionError(
'{}.__services__ must be defined with a list of component classes'
.format(name))
else:
service_classes = state['__services__']
for service_class in service_classes:
mcs._assert_is_compatible_class(name, service_class)
discovered = AutoDiscoverConnections(service_classes)
provides = state.get('__provides__', None)
if provides is None or not isinstance(provides,
(list, tuple, AutoProvide)):
raise DomainDefinitionError(
'{}.__provides__ must be defined with a list of port names'.
format(name))
else:
if isinstance(provides,
AutoProvide): # auto-discover provides ports
auto_provider = provides
provides_ports = auto_provider.filter(
discovered.get_provides())
else:
for port_name in provides:
if port_name not in discovered.get_provides():
msg = '"{}" listed in {}.__provides__ is not provided by any of the services'.format(
port_name,
name,
)
raise DomainDefinitionError(msg)
provides_ports = provides
# all unsatisfied deps are exposed as dependencies of the domain
state['deps'] = deps = PortArray()
for port_name in discovered.unsatisfied_needs():
deps.add_port(port_name)
# make a shadow copy of template_funcs. Used mainly for tracking intended interfaces for ports so we can
# use for validation during testing. At some point we might use this for wiring-time checks too to ensure
# compatibility between ports.
deps._needs_template_funcs = template_funcs = {}
for port in deps.get_ports():
template_func = mcs._assert_providers_compatible_and_extract_template_func(
providers=discovered._needs[port],
port_name=port,
)
template_funcs[port] = template_func
# declared 'provides' ports are registered and entry points created
state['meta'] = meta = DomainProviderMetadata()
for port in provides_ports:
provider = discovered.get_provider(port_name=port)
if not issubclass(provider, (Service, Domain)):
msg = 'Port of non-service class ({}.{}) cannot be published on the domain'.format(
provider.__name__, port)
raise DomainDefinitionError(msg)
inherited_flags = provider.get_provider_flags(port)
inherited_flags.pop('with_name',
None) # don't inherit name-change flags
meta.register_provider(port_name=port,
service=provider,
flags=inherited_flags)
state[port] = generate_domain_method(port_name=port,
provider=provider)
return type.__new__(mcs, name, bases, state)