Ensure no remote connections during testing (#3328)

As a way to prevent the test suite from making remote calls to anywhere
unexpected, use the `pytest-socket` plugin to disable any calls to
hosts other than localhost.

Signed-off-by: Mike Fiedler <miketheman@gmail.com>

dev-requirements.txt

@@ -21,7 +21,9 @@ quart-trio==0.11.1
 # https://github.com/pgjones/hypercorn/issues/169
 hypercorn @ git+https://github.com/urllib3/hypercorn@urllib3-changes
 httpx==0.25.2
+pytest-socket==0.7.0
 # CFFI is not going to support CPython 3.13 in an actual release until
 # there is a release candidate for 3.13.
 # https://github.com/python-cffi/cffi/issues/23#issuecomment-1845861410
 cffi @ git+https://github.com/python-cffi/cffi@14723b0bbd127790c450945099db31018d80fa83; python_version == "3.13"
+

noxfile.py

@@ -88,6 +88,9 @@ def tests_impl(
         "--durations=10",
         "--strict-config",
         "--strict-markers",
+        "--disable-socket",
+        "--allow-unix-socket",
+        "--allow-hosts=localhost,::1,127.0.0.0,240.0.0.0",  # See `TARPIT_HOST`
         *pytest_extra_args,
         *(session.posargs or ("test/",)),
         env=pytest_session_envvars,