Fix: Resolve JSONB cast error in get_latest_comments method

[willardy101-ank]

Pull Request description

Problem

When clicking the Home page in FACT 4.2, users encounter a database error:
CAST(anon_1.jsonb_array_elements_1 AS JSONB)['time'] DESC

This occurs because SQLAlchemy 2.0 automatically adds CAST operations when using dictionary-style access on JSONB columns, resulting in invalid PostgreSQL syntax.

Root Cause

The original code used:

query = select(subquery).order_by(subquery.c.jsonb_array_elements['time'].desc())
SQLAlchemy translates this into a CAST operation on already-unpacked JSONB array elements, which PostgreSQL rejects.

Solution
Add explicit column label to the JSONB array elements
Use SQLAlchemy's text() function with PostgreSQL's native -> operator
This bypasses SQLAlchemy's automatic type conversion

Changes
Modified get_latest_comments() method in src/storage/db_interface_frontend.py
Added text import from sqlalchemy
Used .label('comment_data') for explicit column naming
Used text("comment_data -> 'time' DESC") for ordering

Testing
Verified that Home page loads without database errors
Confirmed that latest comments are displayed correctly
Tested with SQLAlchemy 2.0.30 and PostgreSQL

Additional Notes
This issue affects FACT 4.2 installations. Users experiencing this issue need to:
Apply this fix
Clear Python cache: find . -name "__pycache__" -exec rm -rf {} +
Restart uwsgi processes: pkill -9 -f uwsgi

[jstucke]

Hi and thank you for your contribution. Weirdly enough, I cannot seem to reproduce the error. Which version of PostgreSQL are you using? Does the this test fail for you (without your fix)?

pytest src/test/integration/storage/test_db_interface_frontend.py::test_get_latest_comments

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.97%. Comparing base (14e85ca) to head (b1ae636).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1428   +/-   ##
=======================================
  Coverage   91.97%   91.97%           
=======================================
  Files         372      372           
  Lines       21015    21016    +1     
=======================================
+ Hits        19328    19329    +1     
  Misses       1687     1687           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[jstucke]

Is it possible that the PR tries to fix a bug that is still in the latest release 4.2 but not on the master branch where it was already fixed in #1389?