type annotations and parameter type annotations to
all test functions and helper functions across the 5 transport test
files. This enables mypy to check function bodies, catching type errors
that were previously hidden.
Ruff 0.9 contains a number of formatter changes for the 2025 style guide.
Update to `ruff>=0.9.0` and apply the formatter fixes.
https://astral.sh/blog/ruff-v0.9.0
* Transport tests under tests/transports/
* Protocol tests under tests/protocols/
* IOT tests under iot/
* Plus some minor cleanups, most code changes are related to splitting
up smart & iot tests