Without `if __name__ == "__main__": sys.exit(main())` at the bottom
of cli.py, `python -m cmos.cli format <path>` imports the module
but never invokes main(), so the process silently exits 0 with
empty stdout — indistinguishable from a successful run that
produced no output. Discovered during real-draft testing on
2026-04-11.
Adds a regression test that subprocesses the CLI with --help and
asserts on stdout content. argparse --help exits 0 in both broken
and fixed states; stdout content is the only discriminator.
Both invocation paths now work:
- uv run cmos format <path> (pyproject script entry)
- uv run python -m cmos.cli format <path> (module invocation)
Mark Eaton
22404fbd6b