test: Vorschlagslogik suggest_recurring abgedeckt

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

finance/tests/test_planning_api.py

@@ -1,7 +1,8 @@
 from datetime import date
 from decimal import Decimal
 
-from app.models.tables import Account, Statement
+from app.models.tables import Account, Category, RecurringItem, Statement, Transaction
+from app.services.suggestions import suggest_recurring
 
 H = {"Authorization": "Bearer test-key"}
 
@@ -45,3 +46,56 @@ def test_loan_in_scenario_keeps_balance_positive(client, db):
     body = client.post(f"/api/scenarios/{sc['id']}/project", headers=H,
                        params={"horizon_days": 92, "start_date": "2026-07-15"}).json()
     assert Decimal(body["low_point_balance"]) > Decimal("0")
+
+
+def _tx(acc, d, amount, counterparty, dedup, category_id=None):
+    return Transaction(account_id=acc.id, booking_date=d, amount=Decimal(amount),
+                       purpose="", counterparty=counterparty, status="confirmed",
+                       dedup_hash=dedup, category_id=category_id)
+
+
+def test_suggest_recurring_three_consecutive_months_with_year_wrap(db):
+    acc = Account(bank="dkb", iban="DE01", name="G", type="giro")
+    db.add(acc)
+    db.flush()
+    cat = Category(name="Miete")
+    db.add(cat)
+    db.flush()
+    # Dez 2025 -> Jan 2026 -> Feb 2026: 3 aufeinanderfolgende Monate ueber den
+    # Jahreswechsel hinweg (prueft die Monats-Linearisierung y*12+m).
+    db.add(_tx(acc, date(2025, 12, 1), "-600.00", "Vermieter", "h1", cat.id))
+    db.add(_tx(acc, date(2026, 1, 15), "-600.00", "Vermieter", "h2", cat.id))
+    db.add(_tx(acc, date(2026, 2, 28), "-600.00", "Vermieter", "h3", cat.id))
+    db.commit()
+
+    out = suggest_recurring(db)
+
+    # Median der Tage [1, 15, 28] = 15; Betrag unveraendert uebernommen.
+    assert out == [{"name": "Vermieter", "amount": Decimal("-600.00"),
+                    "rhythm": "monthly", "due_day": 15, "category_id": cat.id}]
+
+
+def test_suggest_recurring_two_months_no_suggestion(db):
+    acc = Account(bank="dkb", iban="DE01", name="G", type="giro")
+    db.add(acc)
+    db.flush()
+    db.add(_tx(acc, date(2026, 3, 10), "-50.00", "Zweimonatig", "h1"))
+    db.add(_tx(acc, date(2026, 4, 10), "-50.00", "Zweimonatig", "h2"))
+    db.commit()
+
+    assert suggest_recurring(db) == []
+
+
+def test_suggest_recurring_excludes_existing_recurring_item(db):
+    acc = Account(bank="dkb", iban="DE01", name="G", type="giro")
+    db.add(acc)
+    db.flush()
+    db.add(_tx(acc, date(2026, 1, 5), "-30.00", "Streaming", "h1"))
+    db.add(_tx(acc, date(2026, 2, 5), "-30.00", "Streaming", "h2"))
+    db.add(_tx(acc, date(2026, 3, 5), "-30.00", "Streaming", "h3"))
+    db.add(RecurringItem(name="Streaming", amount=Decimal("-30.00"),
+                         rhythm="monthly", due_day=5))
+    db.commit()
+
+    # Gleicher Name + Betrag wie ein bereits vorhandenes RecurringItem -> ausgelassen.
+    assert suggest_recurring(db) == []