test.py

import io
import sys
sys.stdout = buffer = io.StringIO()
from app import fizz_buzz
# from app import my_function
import pytest
import app
import os
import re
path = os.path.dirname(os.path.abspath(__file__))+'/app.py'

@pytest.mark.it('The function fizz_buzz should exist')
def test_function_existence():
    try:
        app.fizz_buzz
    except AttributeError:
        raise AttributeError('The function fizz_buzz should exist')

@pytest.mark.it('Use a for loop')
def test_for_loop():
    with open(path, 'r') as content_file:
        content = content_file.read()
        regex = re.compile(r"for\s*")
        assert bool(regex.search(content)) == True
    
@pytest.mark.it('Your function needs to print the correct output')
def test_for_function_output(capsys):
    fizz_buzz()
    captured = capsys.readouterr()
    assert  "1\n2\nFizz\n4\nBuzz\nFizz\n7\n8\nFizz\nBuzz\n11\nFizz\n13\n14\nFizzBuzz\n16\n17\nFizz\n19\nBuzz\nFizz\n22\n23\nFizz\nBuzz\n26\nFizz\n28\n29\nFizzBuzz\n31\n32\nFizz\n34\nBuzz\nFizz\n37\n38\nFizz\nBuzz\n41\nFizz\n43\n44\nFizzBuzz\n46\n47\nFizz\n49\nBuzz\nFizz\n52\n53\nFizz\nBuzz\n56\nFizz\n58\n59\nFizzBuzz\n61\n62\nFizz\n64\nBuzz\nFizz\n67\n68\nFizz\nBuzz\n71\nFizz\n73\n74\nFizzBuzz\n76\n77\nFizz\n79\nBuzz\nFizz\n82\n83\nFizz\nBuzz\n86\nFizz\n88\n89\nFizzBuzz\n91\n92\nFizz\n94\nBuzz\nFizz\n97\n98\nFizz\nBuzz\n" in captured.out