fix: warn when observable mimeType is image/jpg

[forest-savage1234]

Warn when observable:mimeType is image/jpg

Closes #50.

Repo rules (casework/CASE-Mapping-Python): no CONTRIBUTING, no PR template. Open against main. CI is .github/workflows/ci.yml. Boxes match commands actually run on this box after PATCH.diff.

• pre-commit run --all-files
• poetry run mypy case_mapping example.py tests
• poetry run pytest --doctest-modules
• poetry run python example.py

Do not drop Bundle. Do not reopen UCO #363.

Summary

image/jpg is a typo (IANA Media Types registry; RFC 2046 uses image/jpeg). Alex asked whether warnings.warn should fire when that string is used.

ContentDataFacet and FileFacet (the live class; there is no FacetFile) now warn(..., UserWarning) when the mime argument is exactly image/jpg. The value is still stored. No ontology change. UCO #363 is not reopened.

Validation

Shallow clone of casework/CASE-Mapping-Python main @ ea0ee6645ba10135e3c4232e79fb8bbb5e34f50c (2026-07-20 5:36am AKDT) in /workspace/checkouts/CASE-Mapping-Python. PATCH.diff applied (patch -p1). Identity for any later commit: Forest Savage forestsavage03@gmail.com. Nothing posted. Ran on Python 3.13.5 / Poetry 2.4.1 (CI matrix is 3.10 and 3.14; those were not on this box).

$ pre-commit run --all-files
[INFO] Initializing environment for https://github.com/psf/black.
[INFO] Initializing environment for https://github.com/pycqa/isort.
[INFO] Installing environment for https://github.com/psf/black.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
[INFO] Installing environment for https://github.com/pycqa/isort.
[INFO] Once installed this environment will be reused.
[INFO] This may take a few minutes...
check json...............................................................Passed
pretty format json.......................................................Passed
black....................................................................Passed
flake8...................................................................Passed
isort (python)...........................................................Passed

Exit 0.

$ poetry run mypy case_mapping example.py tests
Success: no issues found in 20 source files

Exit 0.

$ poetry run pytest --doctest-modules
============================= test session starts ==============================
platform linux -- Python 3.13.5, pytest-9.0.3, pluggy-1.6.0
rootdir: /workspace/checkouts/CASE-Mapping-Python
configfile: pyproject.toml
collected 4 items

case_mapping/base.py .                                                   [ 25%]
tests/test_duplicate.py ..                                               [ 75%]
tests/test_version.py .                                                  [100%]

============================== 4 passed in 0.08s ===============================

Exit 0.

$ poetry run python example.py

Exit 0. Wrote 80844 bytes to stdout (same size as committed case.jsonld).

Review snippet (not a CI box): ContentDataFacet/FileFacet with image/jpeg produced 0 warnings; image/jpg produced 2 UserWarnings (observable:mimeType 'image/jpg' is not an IANA media type; use 'image/jpeg'.). class Bundle remains at case_mapping/uco/core.py:65.

Files

1. case_mapping/uco/observable.py (ContentDataFacet.__init__, FileFacet.__init__)

Out of scope

• Mapping-Python Generic ObservableObjects should be avoided when other classes exist #43 (example Device)
• Mapping-Python uco-core:Bundle should not to be used #18 (Graph / Bundle)
• Coercing image/jpg → image/jpeg
• A general media-type validator
• A CASE/UCO 1.5.0 pin
• UCO #363
• Dropping or rewriting Bundle

How to review

import warnings
from case_mapping.uco.observable import ContentDataFacet, FileFacet

with warnings.catch_warnings(record=True) as w:
    warnings.simplefilter("always")
    ContentDataFacet(mime_type="image/jpeg")
    FileFacet(file_mime_type="image/jpeg")
    assert w == []
    ContentDataFacet(mime_type="image/jpg")
    FileFacet(file_mime_type="image/jpg")
    assert len(w) == 2
    assert all(issubclass(x.category, UserWarning) for x in w)

warn was already imported in this file (used by OperatingSystemFacet).

Volunteer stand-down

I am a volunteer. If warn-on-construct is the wrong layer, or if you wanted a hard error instead, I will stand down.

I am a volunteer. Thank you for the time. I am trying to become more useful on this work, so I welcome a critical look. If this is the wrong cut, or you want me to stand down, say so and I will recut from notes.

If a warning is the wrong tool, say so and I will stand down.

[forest-savage1234]

Thank you for the time on this review. This only warns when an observable mimeType is image/jpg. If that is the wrong cut, say so and I will recut from notes.