Allow emtpy BNFCR cash through (#9247)

Author: Martin-Molinero

Common/Util/CashAmountUtil.cs

@@ -31,7 +31,8 @@ public static class CashAmountUtil
         public static bool ShouldAddCashBalance(CashAmount balance, string accountCurrency)
         {
             // Don't add zero quantity currencies except the account currency
-            return balance.Amount != 0 || balance.Currency == accountCurrency;
+            // we do add 'BNFCR' even if zero as it's used to track brokerage fees, we need lean to setup conversion rates for it
+            return balance.Amount != 0 || balance.Currency == accountCurrency || balance.Currency == "BNFCR";
         }
     }
-}
+}

Tests/Engine/Setup/BrokerageSetupHandlerTests.cs

@@ -617,6 +617,7 @@ public void ZeroQuantityCurrenciesAreNotAddedToCashBook()
             {
                 new CashAmount(0, "USD"),
                 new CashAmount(0, "EUR"),
+                new CashAmount(0, "BNFCR"),
                 new CashAmount(123, "ETH")
             });
 
@@ -639,6 +640,8 @@ public void ZeroQuantityCurrenciesAreNotAddedToCashBook()
             Assert.IsFalse(algorithm.Portfolio.CashBook.ContainsKey("EUR"));
             // ETH should be present
             Assert.IsTrue(algorithm.Portfolio.CashBook.ContainsKey("ETH"));
+            // special case used in binance future fees
+            Assert.IsTrue(algorithm.Portfolio.CashBook.ContainsKey("BNFCR"));
         }
 
         private void TestLoadExistingHoldingsAndOrders(IAlgorithm algorithm, Func<List<Holding>> getHoldings, Func<List<Order>> getOrders, bool expected)