Cenário 2 do artigo: https://elyssonmr.com/blog/posts/20241231_tests_hints/

helpers.py

from typing import Union
from io import BytesIO

from scenario2.nf_client import get_nf_data
from scenario2.pdf_service import generate_pdf


def issue_nota_fiscal(nf_id: str) -> BytesIO:
    nf_data = get_nf_data(nf_id)
    template = 'nf_pdf.template'

    return generate_pdf(nf_data, template)

nf_client.py

from typing import Union


def get_nf_data(nf_id: str) -> dict[str, Union[int, float, str, dict]]:
    # Should retrieve Nota Fiscal from an API
    pass

pdf_service.py

from io import BytesIO
from typing import Union


def generate_pdf(
    data: dict[str, Union[int, float, str, dict]],
    template: str
) -> BytesIO:
    # Should generate PDF with the given template and data
    pass

test_issue_nota_fiscal.py

from io import BytesIO
from unittest.mock import patch

import pytest

from scenario2.helpers import issue_nota_fiscal


@pytest.fixture
def mock_get_nf_data():
    with patch('scenario2.helpers.get_nf_data') as patched:
        yield patched


@pytest.fixture
def mock_generate_pdf():
    with patch('scenario2.helpers.generate_pdf') as patched:
        yield patched


def test_should_issue_nota_fiscal(mock_get_nf_data, mock_generate_pdf):
    nf_id = '123456'
    template = 'nf_pdf.template'
    nf_data = {'nome': 'test_mock', 'products': [{'name': 'product1', 'value': 10.50}]}
    pdf = BytesIO(b'pdf_bytes')
    mock_get_nf_data.return_value = nf_data
    mock_generate_pdf.return_value = pdf

    generated_pdf = issue_nota_fiscal(nf_id)

    mock_get_nf_data.assert_called_once_with(nf_id)
    mock_generate_pdf.assert_called_once_with(nf_data, template)
    assert generated_pdf == pdf