Mypy issues

[jaredclaypoole]

Summary

• Mypy, as currently configured, fails to run with poetry run mypy
• The current mypy settings are hiding real typing issues in the repo
  • It would take time and effort to resolve all the mypy issues, but we'd certainly fix some real typing issues and possibly some algorithm issues

Details

• When I refer to running mypy, I'm referring to poetry run mypy

• The pinned version of mypy (v1.10.1) fails to run (with an internal error) on the current dev branch

  • Upgrading mypy (to the latest 1.x version, v1.20.2) resolves the issue

    • After upgrading, just one mypy error is reported with the current settings:

      imap_processing/spice/pointing_frame.py:270: error: Need type annotation for "pointing_segments" [var-annotated]

      Found 1 error in 1 file (checked 225 source files)

      • The error is kind of silly; apparently mypy doesn't know that np.zeros returns type np.ndarray.
        Other errors discussed below are more serious.
      • Same result with the latest stable version of mypy, v2.3.0

• The mypy settings in pyproject.toml currently contain the line

  follow_imports = 'skip' #may want to remove

  Note the comment saying we may want to remove this!

  • Including this line introduces a few issues, such as hiding some real mypy errors.

  • Removing "follow_imports = 'skip'" and running mypy with the current mypy version (v1.10.1) yields many errors:

    Found 234 errors in 62 files (checked 225 source files)

    • A lot of these are issues like "expected ndarray; got DataArray" or similar,
      which expose mismatches between our declared APIs and their usage.

  • Removing this line and running mypy after the mypy upgrade (so using mypy v1.20.2) yields slightly fewer errors:

    Found 220 errors in 60 files (checked 225 source files)

    • Same results when running the latest stable version of mypy, v2.3.0