quadratic_function_unit_test.py

import unittest

from quadratic_function import QuadraticFunction


class MyTestCase(unittest.TestCase):

    def test_b_zero(self):
        f = QuadraticFunction(1, 0, -1)
        root_0, root_1 = sorted(f.solve())
        self.assertAlmostEqual(root_0, -1)
        self.assertAlmostEqual(root_1, 1)
        self.assertAlmostEqual(f.y_for(root_0), 0)
        self.assertAlmostEqual(f.y_for(root_1), 0)

    def test_c_zero(self):
        f = QuadraticFunction(1, -1,0)
        root_0, root_1 = sorted(f.solve())
        self.assertAlmostEqual(root_0, 0)
        self.assertAlmostEqual(root_1, 1)
        self.assertAlmostEqual(f.y_for(root_0), 0)
        self.assertAlmostEqual(f.y_for(root_1), 0)

    def test_determinant_zero(self):
        f = QuadraticFunction(1, 2, 1)
        roots = sorted(f.solve())
        self.assertEqual(len(roots), 1)
        self.assertAlmostEqual(roots[0], -1)
        self.assertAlmostEqual(f.y_for(roots[0]), 0)

    def test_determinant_negative(self):
        f = QuadraticFunction(4, 1, 4)
        roots = sorted(f.solve())
        self.assertEqual(len(roots), 0)


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