broker-sync/broker_sync/providers/trading212.py
Viktor Barzin 73b03b227e Add Trading212 ticker normalisation
Context
-------
Phase 1 kickoff: Trading212 tags every ticker with `_EQ`, sometimes
preceded by a lowercase exchange letter ("l" = LSE) or `_US`. Raw
symbols like `VUAGl_EQ` are an implementation detail that would leak
into Wealthfolio and diverge from other providers (InvestEngine and
Schwab emit `VUAG` / `META`). The canonical form has to match across
providers so portfolio aggregation lines up.

Unlike the finance/ reference code, we do NOT restrict to a
SUPPORTED_TICKERS allowlist here — Wealthfolio is the source of truth,
everything gets imported, and the user decides what to track.

This change
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- broker_sync/providers/trading212.py: pure `_normalise_ticker`
  helper backed by a single regex that peels `(_US)?[a-z]?_EQ`. No
  lookup tables — the rule covers all observed shapes.
- tests/providers/test_trading212_ticker.py: parametrised cases for
  every mapping called out in the Phase 1 plan plus pass-through of
  already-canonical symbols.

Test plan
---------
## Automated
- poetry run pytest -q  →  41 passed in 0.46s
- poetry run mypy broker_sync tests  →  Success: no issues found in 22 source files
- poetry run ruff check .  →  All checks passed!

## Manual Verification
Not applicable — pure function, no external side effects.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-17 19:29:23 +00:00

15 lines
446 B
Python

from __future__ import annotations
import re
_SUFFIX_RE = re.compile(r"(?:_US)?(?:[a-z])?_EQ$")
def _normalise_ticker(raw: str) -> str:
"""Strip T212's exchange-suffix decoration from a ticker.
T212 tags every ticker with `_EQ`, optionally preceded by a lowercase
letter ("l" for LSE) or `_US` for a US listing. Peel those off so the
symbol matches what Schwab / InvestEngine emit.
"""
return _SUFFIX_RE.sub("", raw)