Populate NewsTick with its originating contract

tickNews was receiving the market-data reqId as `_reqId` (unused), so
emitted news headlines had no way to signal which symbol they belonged to
when more than one subscription was streaming news at once.

Look up the reqId in `reqId2Ticker` (falling back to `_reqId2Contract`)
and attach a `Contract.recreate(...)` snapshot to the `NewsTick`.

Fixes #110
Fixes #214

Author: mahimn01

ib_async/ib.py

@@ -209,7 +209,8 @@ class IB:
           A profit- and loss entry for a single position is updated.
 
         * ``tickNewsEvent`` (news: :class:`.NewsTick`):
-          Emit a new news headline.
+          Emit a new news headline with the associated contract when
+          available.
 
         * ``newsBulletinEvent`` (bulletin: :class:`.NewsBulletin`):
           Emit a new news bulletin.

ib_async/objects.py

@@ -452,6 +452,7 @@ class NewsTick:
     articleId: str
     headline: str
     extraData: str
+    contract: Contract | None = None
 
 
 @dataclass(slots=True, frozen=True)

ib_async/wrapper.py

@@ -440,6 +440,21 @@ def _endReq(self, key, result=None, success=True):
                 else:
                     future.set_exception(result)
 
+    def _snapshotContractForReqId(self, reqId: int) -> Contract | None:
+        """
+        Return a stable contract snapshot for a market-data request id.
+
+        Prefer the live ticker mapping because that is the primary owner of
+        market-data request identity. Fall back to the generic request
+        contract map when no ticker is registered for the reqId.
+        """
+        ticker = self.reqId2Ticker.get(reqId)
+        if ticker:
+            return Contract.recreate(ticker.contract)
+
+        contract = self._reqId2Contract.get(reqId)
+        return Contract.recreate(contract) if contract else None
+
     def startTicker(self, reqId: int, contract: Contract, tickType: int | str):
         """
         Start a tick request that has the reqId associated with the contract.
@@ -1514,14 +1529,21 @@ def newsProviders(self, newsProviders: list[NewsProvider]):
 
     def tickNews(
         self,
-        _reqId: int,
+        reqId: int,
         timeStamp: int,
         providerCode: str,
         articleId: str,
         headline: str,
         extraData: str,
     ):
-        news = NewsTick(timeStamp, providerCode, articleId, headline, extraData)
+        news = NewsTick(
+            timeStamp,
+            providerCode,
+            articleId,
+            headline,
+            extraData,
+            contract=self._snapshotContractForReqId(reqId),
+        )
         self.newsTicks.append(news)
         self.ib.tickNewsEvent.emit(news)
 

tests/test_news.py

@@ -0,0 +1,64 @@
+import ib_async as ibi
+from ib_async import IB, Stock
+from ib_async.ticker import Ticker
+
+
+def test_tickNews_populates_contract_from_active_ticker():
+    """When a ticker is registered for the incoming reqId (the normal
+    streaming-news flow via reqMktData), the emitted NewsTick carries the
+    originating contract as a typed snapshot."""
+    ib = IB()
+    contract = Stock("AAPL", "SMART", "USD")
+    ib.wrapper.reqId2Ticker[1] = Ticker(contract=contract, defaults=ib.wrapper.defaults)
+
+    captured: list[ibi.NewsTick] = []
+    ib.tickNewsEvent += captured.append
+
+    ib.wrapper.tickNews(
+        1,
+        1_700_000_000,
+        "BRFG",
+        "BRFG$abc",
+        "Apple announces new chip",
+        "",
+    )
+
+    assert len(captured) == 1
+    news = captured[0]
+    assert news.headline == "Apple announces new chip"
+    assert news.contract is not None
+    assert news.contract.symbol == "AAPL"
+    assert news.contract.secType == "STK"
+    # recreate() returns a new instance so the snapshot is independent of
+    # later mutations on the original contract.
+    assert news.contract is not contract
+
+
+def test_tickNews_falls_back_to_reqId2Contract():
+    """When no ticker is registered but the reqId exists in the generic
+    request-contract map, the fallback lookup still populates the contract."""
+    ib = IB()
+    contract = Stock("MSFT", "SMART", "USD")
+    ib.wrapper._reqId2Contract[42] = contract
+
+    captured: list[ibi.NewsTick] = []
+    ib.tickNewsEvent += captured.append
+
+    ib.wrapper.tickNews(42, 1_700_000_000, "BRFG", "BRFG$x", "Headline", "")
+
+    assert len(captured) == 1
+    assert captured[0].contract is not None
+    assert captured[0].contract.symbol == "MSFT"
+
+
+def test_tickNews_contract_none_when_reqId_unknown():
+    """When neither map knows the reqId, the NewsTick still emits with
+    contract=None rather than raising."""
+    ib = IB()
+    captured: list[ibi.NewsTick] = []
+    ib.tickNewsEvent += captured.append
+
+    ib.wrapper.tickNews(999, 1_700_000_000, "BRFG", "BRFG$x", "Headline", "")
+
+    assert len(captured) == 1
+    assert captured[0].contract is None