enhance QueryRecorder to track which database bind is used for each query

Replace flask_sqlalchemy's get_recorded_queries with SQLAlchemy event listeners that capture the bind_key for each engine. Add QueryInfo dataclass with statement, parameters, and bind_key fields. This enables tests to verify that queries are being routed to the correct database when using db.session_bulk.
This is an alternative to the existing PR pallets-eco/flask-sqlalchemy#1403 for flask-sqlalchemy.

Author: spatel033

tests/utils.py

@@ -1,14 +1,46 @@
-import flask_sqlalchemy
+from dataclasses import dataclass
+
+from sqlalchemy import event
+
+from app import db
+
+
+@dataclass
+class QueryInfo:
+    statement: str
+    parameters: tuple | dict | None
+    bind_key: str | None
 
 
 class QueryRecorder:
     def __init__(self):
-        self.queries = []
-        self._count_on_enter = None
+        self.queries: list[QueryInfo] = []
+        self._listeners = []
 
     def __enter__(self):
-        self._count_on_enter = len(flask_sqlalchemy.record_queries.get_recorded_queries())
+        # Register listeners for all engines to capture bind_key
+        for bind_key, engine in db.engines.items():
+            listener = self._listener(bind_key)
+            event.listen(engine, "before_cursor_execute", listener)
+            self._listeners.append((engine, listener))
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
-        self.queries = flask_sqlalchemy.record_queries.get_recorded_queries()[self._count_on_enter :]
+        # Remove all listeners
+        for engine, listener in self._listeners:
+            event.remove(engine, "before_cursor_execute", listener)
+        self._listeners.clear()
+
+    def _listener(self, bind_key):
+        """Create a listener function that captures the bind_key in its closure."""
+
+        def listener(conn, cursor, statement, parameters, context, executemany):
+            self.queries.append(
+                QueryInfo(
+                    statement=statement,
+                    parameters=parameters,
+                    bind_key=bind_key,
+                )
+            )
+
+        return listener