pytest-get-started.py

import pytest
from funcs import capital_case
from funcs import Wallet

#Simple Assertion
def test_capital_case():
    assert capital_case("holy") == "Holy"


#Raise an error if our function is not handling an exception of type. It's more like a test of error handling
def test_raises_exception_on_non_string_arguments():
    with pytest.raises(TypeError):
        capital_case(9)


#Testing a class and its instance/method
def test_initial_balance():
    mywallet = Wallet()
    assert mywallet.init_balance == 0 

#Testing a class and its instance/method
def test_deposit():
    mywallet = Wallet()
    mywallet.deposit(10)
    assert mywallet.init_balance == 10


#Pytest Fixture: it saves repetitions by creating a fixture that could be called over and over, as following (as param & instance):
@pytest.fixture
def wallet():
    return Wallet()

    wallet.deposit(10)
    wallet.spend(5)
    assert wallet.init_balance == 5


#Parameterized Test Functions/Decorators: passing several data sets for testing, as a decorator:
@pytest.mark.parametrize("earned, spent, expected", [(30, 10, 20), (20, 2, 18), (15, 5, 10),])
def test_transactions(earned, spent, expected):
    my_wallet = Wallet()
    my_wallet.deposit(earned)
    my_wallet.spend(spent)
    assert my_wallet.init_balance == expected