def test_normal():
"""Test roundrobin."""
# three tuples of different sizes
data1, data2, data3 = iter('ABC'), iter('D'), iter('EF')
res = roundrobin(data1, data2, data3)
assert next(res) == 'A'
assert list(res) == ['D', 'E', 'B', 'F', 'C']
assert list(data1) == []
assert list(data2) == []
assert list(data3) == []
# three tuples of different sizes in ascending order
data1, data2, data3 = iter('A'), iter('BC'), iter('DEF')
res = roundrobin(data1, data2, data3)
assert next(res) == 'A'
assert list(res) == ['B', 'D', 'C', 'E', 'F']
assert list(data1) == []
assert list(data2) == []
assert list(data3) == []
# one tuple
data = iter('ABC')
res = roundrobin(data)
assert next(res) == 'A'
assert list(res) == ['B', 'C']
assert list(data) == []
# empty tuple
data = ()
res = roundrobin(data)
assert list(res) == []
# nothing
res = roundrobin()
assert list(res) == []
def test_normal_peek():
"""Test roundrobin with peeking at iterable."""
# three tuples of different sizes
data1, data2, data3 = iter('ABC'), iter('DE'), iter('FG')
res = roundrobin(data1, data2, data3)
assert list(islice(res, 3)) == ['A', 'D', 'F']
assert next(data1) == 'B'
assert list(res) == ['C', 'E', 'G']
assert list(data1) == []
assert list(data2) == []
assert list(data3) == []
# three tuples of different sizes in ascending order
data1, data2, data3 = iter('A'), iter('BC'), iter('DEF')
res = roundrobin(data1, data2, data3)
assert next(res) == 'A'
assert next(data2) == 'B'
assert list(res) == ['C', 'D', 'E', 'F']
assert list(data1) == []
assert list(data2) == []
assert list(data3) == []
# one tuple
data = iter('ABC')
res = roundrobin(data)
assert next(res) == 'A'
assert next(data) == 'B'
assert list(res) == ['C']
assert list(data) == []
