def configure(defaults, metadata, loader):
"""
Build a fresh configuration.
:params defaults: a nested dictionary of keys and their default values
:params metadata: the graph metadata
:params loader: a configuration loader
"""
config = Configuration(defaults)
config.merge(loader(metadata))
validate(defaults, metadata, config)
return config
def test_merge():
"""
Configuration support recursive merging
"""
config = Configuration(nested=dict(
nested_key="nested_value",
other_key="initial_value",
))
config.merge(
key="value",
nested=dict(other_key="new_value", ),
)
assert_that(config.key, is_(equal_to("value")))
assert_that(config.nested.nested_key, is_(equal_to("nested_value")))
assert_that(config.nested.other_key, is_(equal_to("new_value")))
config.merge(dict(key=dict()), )
assert_that(config.key, is_(equal_to(dict())))
def test_dont_merge():
"""
Configuration support disabling recursive merging
"""
config = Configuration(nested=dict(
__merge__=False,
nested_key="nested_value",
other_key="initial_value",
))
config.merge(
key="value",
nested=dict(other_key="new_value", ),
)
assert_that(config.key, is_(equal_to("value")))
assert_that(
calling(getattr).with_args(config.nested, "nested_key"),
raises(AttributeError),
)
assert_that(config.nested.other_key, is_(equal_to("new_value")))
def test_merge_lists():
"""
Configuration merges lists but not tuples.
"""
config = Configuration(
lst1=[1, 2],
lst2=[1, 2],
tpl1=(1, 2),
tpl2=(1, 2),
)
config.merge(
lst1=[3, 4],
lst2=(3, 4),
tpl1=(3, 4),
tpl2=[3, 4],
)
assert_that(config["lst1"], is_(equal_to([1, 2, 3, 4])))
assert_that(config["lst2"], is_(equal_to((3, 4))))
assert_that(config["tpl1"], is_(equal_to((3, 4))))
assert_that(config["tpl2"], is_(equal_to([3, 4])))
def merge(configs):
result = Configuration()
for config in configs:
result.merge(config)
return result