def test_lens_tuple_l():
data = {'hello': 0, 'world': 1}
my_lens = lenses.tuple_l(lenses.getitem('hello'), lenses.getitem('world'))
assert my_lens.get(data) == (0, 1)
assert my_lens.set(data, (3, 4)) == {'hello': 3, 'world': 4}
def test_lens_getitem():
assert lenses.getitem(0).get([1, 2, 3]) == 1
assert lenses.getitem(0).set([1, 2, 3], 4) == [4, 2, 3]
def test_boundlens_get_all():
my_lens = lenses.both.compose(lenses.getitem(1))
assert lens([[1, 2], [3, 4]], my_lens).get_all() == (2, 4)
def test_boundlens_add_lens():
assert lens([1, 2]).add_lens(lenses.trivial) + [3] == [1, 2, 3]
assert lens([1, 2]).add_lens(lenses.getitem(1)).set(3) == [1, 3]
import collections
import pytest
import lenses
from lenses import lens
LensAndState = collections.namedtuple('LensAndState', 'lens state')
lenses_and_states = [
LensAndState(lenses.trivial, None),
LensAndState(lenses.getitem(0), [1, 2, 3]),
LensAndState(lenses.getitem(0), (1, 2, 3)),
LensAndState(lenses.getitem(0), {0: 'hello', 1: 'world'}),
] # yapf: disable
@pytest.fixture(params=lenses_and_states)
def lns(request):
return request.param
# Tests for lens rules and other invariants
def test_get_then_set(lns):
'''if we get from a state and then immediately set it again we
should get back the same state'''
assert lns.lens.set(lns.state, lns.lens.get(lns.state)) == lns.state
def test_set_then_get(lns):
'''if we set a state and immediately get it we should get back what
we set'''
