The note in TODO-refactor-remaining.md said ERSMS's four were structural and
that a fix "would rewrite both models". Both halves were wrong.
flask-sqlalchemy 3.1.1 does ship py.typed; the real blocker was that
`class User(db.Model)` is attribute access, which mypy cannot resolve in a
base-class position.
backend/models.py now declares a named DeclarativeBase with SQLAlchemy 2.0
Mapped[] columns. The Model mixin goes away with the base, so the six legacy
Model.query call sites became db.session selects and the two table names are
spelled out rather than derived.
Verified by driving the real routes through Flask's test client with Firebase
stubbed out -- 16 scenarios covering every one of the six call sites, plus
both CREATE TABLE statements, byte-identical to the submitted version. That
harness caught the one thing review would not have: mapped_column(ForeignKey(
"user.uid")) silently infers VARCHAR(80) from the referenced column, which
had changed the submitted `user_id INTEGER`. An explicit Integer puts it back.
app.py went over the 250-line cap on the way, hence the split; models.py takes
the shebang + exec bit that NLP's nine import-only modules already use, since
__init__.py would make `from models import` unresolvable to mypy while it
still works at runtime. backend/Dockerfile copied only app.py, so it needed
the new file too.
PSD's two are pyflink's MapFunction and KeyedProcessFunction, which ship no
types and are not installed in that venv at all -- a hand-written .pyi would
assert an API nothing here can check. A [[tool.mypy.overrides]] scoped to that
one module turns off disallow_subclassing_any and nothing else.
ERSMS 4 -> 0, PSD 2 -> 0, under --strict. ruff and ruff format clean.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0172dj34FDpao6wsix8ZuCzE
