from unittest import TestCase
import math

from drone_test import circle_area

class CircleAreaTest(TestCase):
    def test_area_1(self):
        self.assertEqual(circle_area(1), math.pi)

    def test_area_2(self):
        self.assertEqual(circle_area(2), math.pi * 4)

    def test_negative(self):
        with self.assertRaises(ValueError):
            circle_area(-1)