rostime canon fix demo

test_canon

from __future__ import division

import pytest
import functools
import hypothesis
import hypothesis.strategies as st


def new_canon(secs, nsecs):
    # canonical form: nsecs is always positive, nsecs < 1 second
    secs_over = nsecs // 1000000000
    secs += secs_over
    nsecs -= secs_over * 1000000000
    return secs, nsecs


def old_canon(secs, nsecs):
    # canonical form: nsecs is always positive, nsecs < 1 second
    while nsecs >= 1000000000:
        secs += 1
        nsecs -= 1000000000
    while nsecs < 0:
        secs -= 1
        nsecs += 1000000000
    return secs, nsecs


# we use min and max (of int32) to be meaningful but not loop for eternity...
@hypothesis.given(st.integers(), st.integers(min_value=-2147483648, max_value=2147483647))
@hypothesis.settings(verbosity=hypothesis.Verbosity.verbose)
def test_valid_canon(s, ns):
    o_s, o_ns = old_canon(s, ns)
    n_s, n_ns = new_canon(s, ns)
    assert n_s == o_s
    assert n_ns == o_ns


if __name__ == '__main__':
    pytest.main(['-s',
        'test_canon.py::test_valid_canon',
    ])