AAA01: no Act block found in test

An Act block is usually a line like result = or a check that an exception is raised. When Flake8-AAA raises AAA01 it could not find an Act block in the indicated test function.

Problematic code

def test_some_text() -> None:
    some = 'some'
    text = 'text'

    some_text = f'{some}_{text}'

    assert some_text == 'some_text'

from pytest import raises

def test() -> None:
    with raises(IndexError):
        list()[0]

Correct code 1

Use result = assignment to indicate the action in the test:

def test_some_text() -> None:
    some = 'some'
    text = 'text'

    result = f'{some}_{some}'

    assert result == 'some_text'

Ensure all Pytest context managers are in the pytest namespace - use pytest.raises() not just raises():

import pytest

def test() -> None:
    with pytest.raises(IndexError):
        list()[0]

Correct code 2

Alternatively, mark your Act block with the # act hint to indicate the action in the test. This can be useful for scenarios where a result can not be assigned, such as tests on functions that return None.

def test_some_text() -> None:
    some = 'some'
    text = 'text'

    some_text = f'{some}_{text}'  # act

    assert some_text == 'some_text'

from pytest import raises

def test() -> None:
    with raises(IndexError):
        list()[0]  # act

Rationale

The Act block carries out a single action on an object so it’s important that Flake8-AAA can clearly distinguish which line or lines make up the Act block in every test.

Flake8-AAA recognises code blocks wrapped in Pytest context managers like pytest.raises() as Act blocks.

It also recognises unittest’s assertRaises() blocks as Act blocks.