fix(simplefin): stop bare thank-you memos dropping purchases from spend

[cursor]

Summary

• Fixes silent spend undercount when merchant memos contain thank you (for example THANK YOU FOR SHOPPING…). Those purchase debits were classified as Credit Card Payment and excluded via NON_SPEND_CATEGORIES.
• Replaces the bare thank you pattern with payment-shaped substrings in the shared categorize_expense path so legitimate PAYMENT - THANK YOU credits/debits still classify correctly.
• Link to related issue(s): Fixes bug: bare "thank you" categorization drops real card purchases from spend #179

Concrete trigger and impact

categorize_expense("THANK YOU FOR SHOPPING AT TARGET T-1234", -87.43, "Platinum Card")
# before: "Credit Card Payment" (non-spend) — purchase dollars vanish from spend totals
# after:  spend-eligible category (e.g. Uncategorized)

Same failure class as the bare credit card substring fixed in #176; introduced on main by #176.

Root cause and shared seam

CATEGORY_PATTERNS["Credit Card Payment"] matched bare "thank you" as a plain substring with no payment-shape requirement. All SimpleFIN expense sync callers go through categorize_expense, so the fix is at that shared pattern list.

Test Plan

• Focused: uv run pytest tests/python/test_categorize.py -q --no-cov — 92 passed
• All non-integration tests: uv run pytest -m "not integration" -q — 1188 passed, 1 skipped, coverage 83.41%
• Lint: uv run ruff format --check + uv run ruff check on touched files — clean
• Types: uv run mypy src/ — Success, 96 source files

Overlap check

Live open PRs at start and before open: none. Searched open/closed issues and PRs for thank you / categorize / Credit Card Payment; only related history is merged #176 (introducer). No open PR touches categorize.py.

Review Checklist

• No secrets or PII committed
• Documentation updated (if applicable) — N/A (skills docs are issues-only; Python path + regression test only)
• Test coverage maintained or improved

Wiki impact

• No Wiki update is required.
• Wiki updated — affected pages and Wiki commit:

Generated with Cursor; I reviewed, ran the tests, and verified behavior before submitting.

  

[coderabbitai]

Important

Review skipped

Bot user detected.

To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: e55d6564-c31b-46cb-9840-95d54e2a37f7

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}