Add chunking tests

pyproject.toml

@@ -113,14 +113,20 @@ asyncio_mode = "auto"
 asyncio_default_fixture_loop_scope = "function"
 log_cli = false
 addopts = "--import-mode=append"
+markers = [
+  "slow: moves enough data to be worth skipping by default (`-m 'not slow'`)",
+]
 
 # tell poe to use the env we give it, otherwise it detects uv and overrides flags
 [tool.poe]
 executor.type = "simple"
 
 [tool.poe.tasks]
 test_proc = "pytest --log-level=1 -W error -n auto -v -rfE --capture=fd tests/test_process.py"
-test_fn = "pytest --log-level=1 -W error -n auto -v -rfE --capture=fd --ignore=tests/test_process.py"
+test_fn = "pytest --log-level=1 -W error -n auto -v -rfE --capture=fd -m 'not slow' --ignore=tests/test_process.py"
+# Skip `--log-level=1` and `-n auto` to allow slow tests to complete without
+# formatting wall of text and to avoid tests using up all memory (~1GB per thread)
+test_slow = "pytest -W error -v -rfE --capture=fd -m slow --ignore=tests/test_process.py"
 debug-test_proc = "pytest --log-level=1 -W error -vvvx -rA --show-capture=no --capture=no tests/test_process.py"
 debug-test_fn = "pytest --log-level=1 -W error -vvvx -rA --show-capture=no --capture=no --ignore=tests/test_process.py"