test_calc.py

from calculator import Calc


def test_successful_calculation():
    test_value = Calc('11+11+11+11+11+11+11+11+11+11+11+11').calculate()
    assert type(test_value) is int
    assert 132 == test_value

    test_value = Calc('1*10-5000000+200').output()
    assert type(test_value) is int
    assert -4999790 == test_value

    test_value = Calc('1*2+3*4-5*6+7*8-9*10+123*456').calculate()
    assert type(test_value) is int
    assert 56038 == test_value

    test_value = Calc('0').calculate()
    assert type(test_value) is int
    assert 0 == test_value

    test_value = Calc('100-10-20-30').calculate()
    assert type(test_value) is int
    assert 40 == test_value


def test_type_error_validate():
    try:
        Calc(345).validate()
    except Exception as e:
        assert type(e) is TypeError
    else:
        assert False, 'No error raised when was expected to.'


def test_syntax_error_validate():
    try:
        Calc('1**2').validate()
    except Exception as e:
        assert type(e) is SyntaxError
    else:
        assert False, 'No error raised when was expected to.'


def test_type_error_output():
     assert 'Wrong input type.' == Calc(123).output()


def test_syntax_error_output():
     assert 'Invalid input syntax.' == Calc('1**2').output()