ordered_pair.py

"""Too many ways to generate pairs of two integers in ascending
order.
"""

from hypothesis import assume, given
import hypothesis.strategies as st
import unittest


class TestAscending(unittest.TestCase):
    @given(a=st.integers(), b=st.integers())
    def test_reject(self, a, b):
        """Reject uninteresting inputs at runtime."""
        assume(a <= b)
        assert a <= b

    @given(a=st.integers(), b=st.integers())
    def test_sort(self, a, b):
        """Re-sort values at runtime."""
        a, b = min(a, b), max(a, b)
        assert a <= b

    @given(values=st.lists(st.integers(), min_size=2, max_size=2).map(sorted))
    def test_sorted(self, values):
        """Directly generate sorted lists."""
        a, b = values
        assert a <= b

    @given(a=st.integers(), data=st.data())
    def test_dynamic_generation(self, a, data):
        """Draw dependent values dynamically"""
        b = data.draw(st.integers(min_value=a))
        assert a <= b

    @given(
        values=st.integers().flatmap(
            lambda a: st.tuples(st.just(a), st.integers(min_value=a))
        )
    )
    def test_nested_generation(self, values):
        """Create a strategy that's parameterised on generated values."""
        a, b = values
        assert a <= b

    @given(a=st.integers(), delta=st.integers(min_value=0))
    def test_reformulate(self, a, delta):
        """Ask for something else."""
        b = a + delta
        assert a <= b


if __name__ == "__main__":
    unittest.main()