import unittest
import io
import re
from unittest import mock
import math
import student_X as main #Replace student_X with your filename 
    
    
    
 

class SphereVolumeTests(unittest.TestCase):

    def test_default_case(self):
        function = main.sphere_volume

        try:
            docstring = function.__doc__
            docstring = docstring.strip()
        except:
            docstring = ""
        correct = docstring != ""
        message = "No docstring."
        self.assertTrue(correct, message) 
        

        test = False
        try:
            correct = 4/3 * math.pi * 132 ** 3
            result = function(132)
            test = correct == result
        except:
            pass
        message = "Doesn't return the correct volume on a bigger sphere."
        self.assertTrue(test, message)


        test = False
        try:
            correct = 4/3 * math.pi * .4 ** 3
            result = function(.4)
            test = correct == result
        except:
            pass
        message = "Doesn't return the correct volume on a smaller sphere."
        self.assertTrue(test, message)
        
        
if __name__ == "__main__":
    tests = SphereVolumeTests()
    tests.test_default_case()