instructor.py

# -*- coding: utf-8 -*-
"""
Created on Thu Jan 25 23:27:40 2018

@author: acbart
"""

import unittest
from unittest.mock import patch
import io
import sys
import importlib

def make_inputs(*input_list):
    '''
    Helper function for creating mock user input.
    
    Params:
        input_list (list of str): The list of inputs to be returned
    Returns:
        function (str=>str): The mock input function that is returned, which
                             will return the next element of input_list each
                             time it is called.
    '''
    generator = iter(input_list)
    def mock_input(prompt=''):
        print(prompt)
        return next(generator)
    return mock_input

class TextExternal(unittest.TestCase):
    maxDiff = None
    
    def run_student(self):
        '''
        Run the students' code; if it has been run before, then we reload
        it instead.
        '''
        if 'student' not in sys.modules:
            import student
        else:
            importlib.reload(sys.modules['student'])
    
    def test_student(self):
        for name in ["AustinCorgiBart", "jrhead"]:
            prompter = make_inputs(name)
            with patch('sys.stdout', new=io.StringIO()) as captured_output:
                with patch('builtins.input', prompter):
                    try:
                        self.run_student()
                    except StopIteration:
                        msg=("Failed to accept input for name '{}'. "
                             "I typed '{}' but it wasn't accepted."
                             ).format(name)
                        self.fail(msg=msg)
            student_output = captured_output.getvalue()
            expected = "Welcome!\nGive me your name:\nHiya, "+name+"\n"
            self.assertEqual(student_output, expected)
        
unittest.main()