Create contract-from-params abstraction

The pattern of creating a specific concrete Contract type from generic
contract arguments was repeated in many places, but we can just
centralize it for cleaner logic and cleaner reuse.

The goal here is to take things like Contract(secType="OPT", ...)
generic contract containers and turn them into more specific Option(...)
objects instead (or any of the other more specific Contract subclasses).

Author: mattsta

ib_async/contract.py

@@ -137,6 +137,11 @@ def create(**kwargs) -> "Contract":
 
         return cls(**kwargs)
 
+    @staticmethod
+    def recreate(c) -> "Contract":
+        """Comply an existing generic Contract into its most specific type."""
+        return Contract.create(**util.dataclassAsDict(c))
+
     def isHashable(self) -> bool:
         """
         See if this contract can be hashed by conId.

ib_async/wrapper.py

@@ -481,7 +481,7 @@ def updatePortfolio(
         realizedPNL: float,
         account: str,
     ):
-        contract = Contract.create(**dataclassAsDict(contract))
+        contract = Contract.recreate(contract)
         portfItem = PortfolioItem(
             contract,
             posSize,
@@ -505,7 +505,7 @@ def updatePortfolio(
     def position(
         self, account: str, contract: Contract, posSize: float, avgCost: float
     ):
-        contract = Contract.create(**dataclassAsDict(contract))
+        contract = Contract.recreate(contract)
         position = Position(account, contract, posSize, avgCost)
         positions = self.positions[account]
 
@@ -604,7 +604,7 @@ def openOrder(
                 order = Order(
                     **{k: v for k, v in dataclassAsDict(order).items() if v != "?"}
                 )
-                contract = Contract.create(**dataclassAsDict(contract))
+                contract = Contract.recreate(contract)
                 orderStatus = OrderStatus(orderId=orderId, status=orderState.status)
                 trade = Trade(contract, order, orderStatus, [], [])
                 self.trades[key] = trade
@@ -628,7 +628,7 @@ def openOrderEnd(self):
         self._endReq("openOrders")
 
     def completedOrder(self, contract: Contract, order: Order, orderState: OrderState):
-        contract = Contract.create(**dataclassAsDict(contract))
+        contract = Contract.recreate(contract)
         orderStatus = OrderStatus(orderId=order.orderId, status=orderState.status)
         trade = Trade(contract, order, orderStatus, [], [])
         self._results["completedOrders"].append(trade)
@@ -720,10 +720,11 @@ def execDetails(self, reqId: int, contract: Contract, execution: Execution):
             key = self.orderKey(execution.clientId, execution.orderId, execution.permId)
             trade = self.trades.get(key)
 
+        # TODO: debug why spread contracts aren't fully detailed here. They have no legs in execDetails, but they do in orderStatus?
         if trade and contract == trade.contract:
             contract = trade.contract
         else:
-            contract = Contract.create(**dataclassAsDict(contract))
+            contract = Contract.recreate(contract)
 
         execId = execution.execId
         isLive = reqId not in self._futures