def test_middleware():
"""
Verify that Middleware can access Resources and that
the Middleware is setup and torndown.
"""
class TestMiddleware(object):
"""
Example middleware that sets it's state at
setup and teardown.
"""
def __call__(self, context):
context.store['state'] = 'setup'
yield
context.store['state'] = 'torndown'
data_store = {}
data_manager = DataManager()
data_manager.register_services(test=TestService())
# Middleware that starts and ends with the context
data_manager.register_context_middleware(
TestMiddleware(),
)
data_manager.register_resources(
store=ValueResource(data_store)
)
with data_manager.dal() as dal:
assert dal.test.get_state() == 'setup'
dal.test.change_state('middle')
assert dal.test.get_state() == 'middle'
assert data_store['state'] == 'torndown'
def test_resource_setup_and_teardown():
"""
Verify that Resources are setup and torndown.
"""
class TestResource(object):
"""
Example resource that sets as state at
setup/teardown.
"""
def __init__(self, store):
self._store = store
def __call__(self, context):
self._store['state'] = 'setup'
yield self._store['state']
self._store['state'] = 'torndown'
store = {}
data_manager = DataManager()
data_manager.register_resources(test_state=TestResource(store))
with data_manager.context() as ctx:
assert 'test_state' not in ctx, 'Resource should be lazy created'
assert ctx.test_state == 'setup', 'Resource should have been setup'
assert store['state'] == 'torndown', 'Resource should have been torndown'
assert len(ctx.get_resource_exit_errors()) == 0
def test_resource_that_has_setup_error():
"""
Verify that a resource that raises an exception on setup
prevents dal context from continuing.
"""
class SetupError(Exception):
pass
def error_resource(context):
if True:
raise SetupError()
pytest.fail('Should never get to the point of yielding')
yield
pytest.fail('Should never recover')
data_manager = DataManager()
data_manager.register_resources(test=error_resource)
with pytest.raises(SetupError):
with data_manager.context() as ctx:
try:
assert ctx.test
except SetupError:
# Expected
raise
else:
pytest.fail('Should have raised SetupError inside context')
# Even though an error occurred during setup, the resource
# never has a chance to recover so can't generate any new
# errors on exit
assert len(ctx.get_resource_exit_errors()) == 0
def test_resource_setup_and_teardown():
"""
Verify that Resources are setup and torndown.
"""
class TestResource(object):
"""
Example resource that sets as state at
setup/teardown.
"""
def __init__(self, store):
self._store = store
def __call__(self, context):
self._store['state'] = 'setup'
yield self._store['state']
self._store['state'] = 'torndown'
store = {}
data_manager = DataManager()
data_manager.register_resources(
test_state=TestResource(store)
)
with data_manager.context() as ctx:
assert 'test_state' not in ctx, 'Resource should be lazy created'
assert ctx.test_state == 'setup', 'Resource should have been setup'
assert store['state'] == 'torndown', 'Resource should have been torndown'
assert len(ctx.get_resource_exit_errors()) == 0
def test_middleware():
"""
Verify that Middleware can access Resources and that
the Middleware is setup and torndown.
"""
class TestMiddleware(object):
"""
Example middleware that sets it's state at
setup and teardown.
"""
def __call__(self, context):
context.store['state'] = 'setup'
yield
context.store['state'] = 'torndown'
data_store = {}
data_manager = DataManager()
data_manager.register_services(test=StateTestService())
# Middleware that starts and ends with the context
data_manager.register_context_middleware(TestMiddleware(), )
data_manager.register_resources(store=ValueResource(data_store))
with data_manager.dal() as dal:
assert dal.test.get_state() == 'setup'
dal.test.change_state('middle')
assert dal.test.get_state() == 'middle'
assert data_store['state'] == 'torndown'
def get_dam():
data_manager = DataManager()
data_manager.register_services(users=UserService().register_services(profile=UserProfileService()))
data_manager.register_resources(
user_db=MockStoreResource(MockStore()), user_profile_db=MockStoreResource(MockStore())
)
return data_manager
def test_resource_that_has_setup_error():
"""
Verify that a resource that raises an exception on setup
prevents dal context from continuing.
"""
class SetupError(Exception):
pass
def error_resource(context):
if True:
raise SetupError()
pytest.fail('Should never get to the point of yielding')
yield
pytest.fail('Should never recover')
data_manager = DataManager()
data_manager.register_resources(test=error_resource)
with pytest.raises(SetupError):
with data_manager.context() as ctx:
try:
assert ctx.test
except SetupError:
# Expected
raise
else:
pytest.fail('Should have raised SetupError inside context')
# Even though an error occurred during setup, the resource
# never has a chance to recover so can't generate any new
# errors on exit
assert len(ctx.get_resource_exit_errors()) == 0
def get_dam():
data_manager = DataManager()
data_manager.register_services(users=UserService().register_services(
profile=UserProfileService()))
data_manager.register_resources(
user_db=MockStoreResource(MockStore()),
user_profile_db=MockStoreResource(MockStore()),
)
return data_manager
def test_register_unique_resource():
"""
Verify you can not register an existing resource
"""
def resource(context):
yield
data_manager = DataManager()
data_manager.register_resources(test=resource)
with pytest.raises(AlreadyExistsException):
data_manager.register_resources(test=resource)
def test_register_unique_resource():
"""
Verify you can not register an existing resource
"""
def resource(context):
yield
data_manager = DataManager()
data_manager.register_resources(test=resource)
with pytest.raises(AlreadyExistsException):
data_manager.register_resources(test=resource)
def test_replace_unique_resource():
"""
Verify you can replace an existing resource
"""
def resource_a(context):
yield 'a'
def resource_b(context):
yield 'b'
data_manager = DataManager()
data_manager.register_resources(test=resource_a)
data_manager.replace_resource('test', resource_b)
with data_manager.context() as ctx:
assert ctx.test == 'b'
def test_replace_unique_resource():
"""
Verify you can replace an existing resource
"""
def resource_a(context):
yield 'a'
def resource_b(context):
yield 'b'
data_manager = DataManager()
data_manager.register_resources(test=resource_a)
data_manager.replace_resource('test', resource_b)
with data_manager.context() as ctx:
assert ctx.test == 'b'
def test_resource_that_yields_too_much():
"""
Verify that a resource that yields more
than once raises a RuntimeError, but is suppressed
"""
def chatty_resource(context):
"""
Resource should only yield once
"""
yield True
yield False
data_manager = DataManager()
data_manager.register_resources(test=chatty_resource)
with data_manager.context() as ctx:
assert ctx.test
assert ctx.get_resource_exit_errors()[0][0] is RuntimeError
def test_resource_that_yields_too_much():
"""
Verify that a resource that yields more
than once raises a RuntimeError, but is suppressed
"""
def chatty_resource(context):
"""
Resource should only yield once
"""
yield True
yield False
data_manager = DataManager()
data_manager.register_resources(test=chatty_resource)
with data_manager.context() as ctx:
assert ctx.test
assert ctx.get_resource_exit_errors()[0][0] is RuntimeError
def test_resource_active_context():
"""
Verify that Resources can not be used if the context is not active.
"""
data_manager = DataManager()
data_manager.register_resources(test=ValueResource(True))
ctx = data_manager.context()
with pytest.raises(RuntimeError):
assert ctx.test
pytest.fail('Resource should not be useable when context has not been setup')
with ctx:
assert ctx.test is True
assert len(ctx.get_resource_exit_errors()) == 0
with pytest.raises(RuntimeError):
assert ctx.test
pytest.fail('Resource should not be useable when context has been torndown')
def test_resource_that_does_not_yield():
"""
Verify that a resource that does not yield raises a
ResourceSetupException and ends the context
"""
def bogus_resource(context):
"""
This is a valid generator function because of the ``yield``
but the ``yield`` will never occur so this is an invalid resource.
Resources must ``yield`` once to be valid.
"""
if False:
yield
data_manager = DataManager()
data_manager.register_resources(test=bogus_resource)
with pytest.raises(ResourceSetupException):
with data_manager.context() as ctx:
assert ctx.test
pytest.fail('Context should not have continued')
assert len(ctx.get_resource_exit_errors()) == 0
def test_resource_active_context():
"""
Verify that Resources can not be used if the context is not active.
"""
data_manager = DataManager()
data_manager.register_resources(test=ValueResource(True))
ctx = data_manager.context()
with pytest.raises(RuntimeError):
assert ctx.test
pytest.fail(
'Resource should not be useable when context has not been setup')
with ctx:
assert ctx.test is True
assert len(ctx.get_resource_exit_errors()) == 0
with pytest.raises(RuntimeError):
assert ctx.test
pytest.fail(
'Resource should not be useable when context has been torndown')
def test_resource_that_does_not_yield():
"""
Verify that a resource that does not yield raises a
ResourceSetupException and ends the context
"""
def bogus_resource(context):
"""
This is a valid generator function because of the ``yield``
but the ``yield`` will never occur so this is an invalid resource.
Resources must ``yield`` once to be valid.
"""
if False:
yield
data_manager = DataManager()
data_manager.register_resources(test=bogus_resource)
with pytest.raises(ResourceSetupException):
with data_manager.context() as ctx:
assert ctx.test
pytest.fail('Context should not have continued')
assert len(ctx.get_resource_exit_errors()) == 0
