SLD1xx - Testing and Dynamic Execution

SLD102: Prohibits use of patch and patch.object from unittest.mock.

Use dependency injection instead of mocking:

# Bad
from unittest.mock import patch

@patch("mymodule.requests.get")
def test_fetch(mock_get):
    ...

# Good
class TestFetch(unittest.TestCase):
    def test_fetch(self) -> None:
        fake_client = FakeHTTPClient(response={"data": 1})
        fetcher = DataFetcher(client=fake_client)
        result = fetcher.fetch()
        assert_that(result, equal_to(1))

SLD103: Prohibits any reference to the dynamic-execution builtins exec, eval, and __import__. These almost always indicate metaprogramming shenanigans that deserve a careful review; if you genuinely need one, silence with # noqa: SLD103 so the choice is visible at the call site. Bare references (e.g. f = exec) are flagged too, since aliasing is just calling with extra steps.

# Bad
def run_user_code(source: str) -> None:
    exec(source)

result = eval(expression)
mod = __import__(name)

# Good
import importlib

def run_user_code(source: str) -> None:
    compiled = compile_in_sandbox(source)
    compiled.run()

mod = importlib.import_module(name)