def test_write_to_empty_sources():
source1 = DictSource(auto_subsection=True)
source2 = DictSource()
config = StackedConfig(source2, source1)
config.a = 10
config['b'].c = 20
assert source1.a == 10
assert source1.b.c == 20
assert source2.dump() == {}
def test_read_source_with_converters():
data = {'a': 1, 'b': {'c': 2}}
converter_list = [
('a', str, int),
('c', lambda v: 2 * v, lambda v: v / 2),
]
config = DictSource(data, converters=converter_list)
assert config.a == '1'
assert config.b.c == 4
assert config.dump() == {'a': '1', 'b': {'c': 4}}