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

class CharTwoStringsTests(unittest.TestCase):

    def test_default_case(self):
        function = main.char_two_strings
        
        test = False
        try:
            incorrect = ""
            result = function.__doc__.strip()
            test = incorrect != result
        except:
            pass

        message = "No docstring."
        self.assertTrue(test, message)

        
        
        inputs = ("", "boy", 2)
        test = False
        correct = 'y'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the first string is empty."
        self.assertTrue(test, message)

        
        
        inputs = ("cheese", "", 2)
        test = False
        correct = 'e'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the second string is empty."
        self.assertTrue(test, message)

        
        
        inputs = ("a", "I", 0)
        test = False
        correct = 'a'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the strings only have one character."
        self.assertTrue(test, message)

        
        
        inputs = ("a", "I", 1)
        test = False
        correct = 'I'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the strings only have one character."
        self.assertTrue(test, message)

        
        
        inputs = ("banana", "boy", 5)
        test = False
        correct = 'a'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the index is in the first string."
        self.assertTrue(test, message)
        

        
        inputs = ("banana", "boy", 7)
        test = False
        correct = 'o'
        if isinstance(inputs, tuple):
            result = function(*inputs)
        else:
            result = function(inputs)
        test = correct == result

        message = "Doesn't work when the index is in the second string."
        self.assertTrue(test, message)
        
        
if __name__ == "__main__":
    tests = CharTwoStringsTests()
    tests.test_default_case()