chore: import upstream snapshot with attribution

backend/chainlit/sync.py

@@ -0,0 +1,36 @@
+import asyncio
+import threading
+from typing import Any, Coroutine, ParamSpec, TypeVar
+
+from asyncer import asyncify
+from syncer import sync
+
+from chainlit.context import context_var
+
+make_async = asyncify
+
+T_Retval = TypeVar("T_Retval")
+T_ParamSpec = ParamSpec("T_ParamSpec")
+T = TypeVar("T")
+
+
+def run_sync(co: Coroutine[Any, Any, T_Retval]) -> T_Retval:
+    """Run the coroutine synchronously."""
+
+    # Copy the current context
+    current_context = context_var.get()
+
+    # Define a wrapper coroutine that sets the context before running the original coroutine
+    async def context_preserving_coroutine():
+        # Set the copied context to the coroutine
+        context_var.set(current_context)
+        return await co
+
+    # Execute from the main thread in the main event loop
+    if threading.current_thread() == threading.main_thread():
+        return sync(context_preserving_coroutine())
+    else:  # Execute from a thread in the main event loop
+        result = asyncio.run_coroutine_threadsafe(
+            context_preserving_coroutine(), loop=current_context.loop
+        )
+        return result.result()