def test_transform_not_none():
def transform(x):
return x + 2
intended = map(transform, [e for e in elems if e is not None])
use = Piper()[:transform:]
assert list(use.run(elems)) == list(intended)
def test_transform_if_keeping_none():
numbers = [1, 2, 3, 4, None, 5, 6, 7, 8]
def transform(x):
return x + 2
intended = [transform(x) if x is not None else x for x in numbers]
use = Piper()[:transform:lambda x: None]
assert list(use.run(numbers)) == list(intended)
def test_transform_if_even():
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
def transform(x):
return x + 2
def condition(x):
return x % 2 == 0
intended = [transform(x) for x in numbers if condition(x)]
use = Piper()[condition:transform:]
assert list(use.run(numbers)) == list(intended)
def test_transform_if_even_odds_are_none():
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
def transform(x):
return x + 2
def condition(x):
return x % 2 == 0
intended = [transform(x) if condition(x) else None for x in numbers]
use = Piper()[condition:transform:lambda x: None]
assert list(use.run(numbers)) == list(intended)
def test_transform_if():
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
def transform(x):
return x + 2
def condition(x):
return x < 6
intended = map(transform, filter(condition, numbers))
use = Piper()[condition:transform:]
assert list(use.run(numbers)) == list(intended)
def test_transform_rails():
numbers = [1, 2, 3, 4, 5, 6, 7, 8]
def transform(x):
return x + 2
def condition(x):
return x < 6
def negative_transform(x):
return "faulty {}".format(x)
intended = [
transform(x) if condition(x) else negative_transform(x)
for x in numbers
]
use = Piper()[condition:transform:negative_transform]
assert list(use.run(numbers)) == list(intended)
def test_transform2_none():
intended = [x if x is not None else "muoio" for x in elems]
use = Piper()[::lambda x: "muoio"]
assert list(use.run(elems)) == intended