Write a Unit Test for function without return value-CodePudding

I have a function that takes a link as input, then requests values, then puts them in an available list, this function doesn't return anything, how can I write test cases for them? For example:

list = []
def myfunc(link):
    [code block]
    list.append(value)

CodePudding user response：

Generally it's not great to use global variables. I'd recommend using something like a class. eg:

class Whatevs:
    def __init__(self):
        self.list = []

    def my_func(self,link):
        [code block]
        self.list.append(value)

Then in your test you can do something like:

instance = Whatevs()
instance.my_func()
assert instance.list == [whatever it should be]

Also, I'd recommend reading PEP8. It just has some stuff about naming that you might find useful

CodePudding user response：

Import the list, clear it, run the function and then check it's value:

from my_module import list, myfunc

def test_myfunc():
  list.clear()
  myfunc()
  assert list == [1, 2, 3]

CodePudding user response：

I don't think it is very clean, but this would work: I made a new file to separate the production code from the testing code. I imported the list (in my code it's l) and test on it. My main.py:

from typing import Any

l = []

def myfunc(link: Any) -> None:
    my_actual_value = "my_expected_value"
    l.append(my_actual_value)

My main_test.py:

import unittest

import main
from main import myfunc

class TestMyFunc(unittest.TestCase):
    def setUp(self) -> None:
        main.l = []

    def test_my_func(self) -> None:
        # Given
        some_link = "some_link"
        my_expected_value = ["my_expected_value"]
        # When
        myfunc(some_link)
        # Then
        assert my_expected_value == main.l

    def test_my_func2(self) -> None:
        # Given
        some_link = "some_link2"
        my_expected_value = ["my_expected_value"]
        # When
        myfunc(some_link2)
        # Then
        assert my_expected_value == main.l