small fixes

backend/tests/test_exchange.py

@@ -17,6 +17,7 @@ from models import (
     TradeDirection,
 )
 from price_fetcher import PAIR_BTC_EUR, SOURCE_BITFINEX
+from shared_constants import EUR_TRADE_INCREMENT
 
 
 def tomorrow() -> date:
@@ -213,7 +214,7 @@ class TestExchangePriceEndpoint:
         assert config["eur_max_buy"] == 300000
         assert config["eur_min_sell"] == 12000
         assert config["eur_max_sell"] == 320000
-        assert config["eur_increment"] == 20
+        assert config["eur_increment"] == EUR_TRADE_INCREMENT
         assert config["premium_buy"] == 5
         assert config["premium_sell"] == 6
 
@@ -659,6 +660,11 @@ class TestCreateExchange:
         """EUR amount not a multiple of increment is rejected."""
         target_date = await setup_availability_and_price(client_factory, admin_user)
 
+        # Calculate an amount that's not a multiple of the increment
+        # Use a valid base amount (multiple of increment) and add a small offset
+        base_amount = 11500  # €115.00
+        invalid_amount = base_amount + (EUR_TRADE_INCREMENT - 1)  # Not a multiple
+
         with mock_price_fetcher(20000.0):
             async with client_factory.create(cookies=regular_user["cookies"]) as client:
                 response = await client.post(
@@ -667,7 +673,7 @@ class TestCreateExchange:
                         "slot_start": f"{target_date}T09:00:00Z",
                         "direction": "buy",
                         "bitcoin_transfer_method": "onchain",
-                        "eur_amount": 11500,  # €115, not multiple of €20
+                        "eur_amount": invalid_amount,
                     },
                 )