quadratic_function_pbt.py

import unittest

from hypothesis import given, strategies, example

from quadratic_function import QuadraticFunction


class MyTestCase(unittest.TestCase):

    @given(
        strategies.floats(
            min_value=-100000,
            max_value=100000
        ), strategies.floats(
            min_value=-100000,
            max_value=100000
        ), strategies.floats(
            min_value=-100000,
            max_value=100000
        ))
    def test_root_always_zero(self, a, b, c):
        f = QuadraticFunction(a, b, c)
        # if not QuadraticFunction.same(a, 0):
        roots = f.solve()
        for x in roots:
            self.assertAlmostEqual(0, f.y_for(x), places=2)

    @given(strategies.floats(), strategies.floats(), strategies.floats())
    def test_negative_determinant_no_result(self, a, b, c):
        f = QuadraticFunction(a, b, c)
        if f.determinant() < 0:
            self.assertEqual(f.solve(), [])

    @given(strategies.floats(), strategies.floats())
    def test_determinant_0_single_result(self, a, c):
        from math import sqrt
        b_prime = 2 * a * c
        if b_prime > 0:
            b = sqrt(b_prime)
            f = QuadraticFunction(a, b, c)
            self.assertEqual(len(f.solve()), 1)


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

#         min_value=-1000,
#         max_value=1000