Preserve supported client annotations

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Copilot-Session: 76f2163a-0773-4889-b627-1bd4e5c7bea0

Author: andystaples

azure-functions-durable/azure/durable_functions/decorators/durable_app.py

@@ -428,7 +428,14 @@ def bind_client(
 
             def set_client_metadata(client_bound: Callable[..., Any]) -> None:
                 annotations = dict(function.__annotations__)
-                annotations.setdefault(client_name, str)
+                supported_client_types = (
+                    str,
+                    bytes,
+                    DurableFunctionsClient,
+                    SyncDurableFunctionsClient,
+                )
+                if annotations.get(client_name) not in supported_client_types:
+                    annotations[client_name] = str
                 client_bound.__annotations__ = annotations
                 setattr(client_bound, "client_function", function)
 

tests/azure-functions-durable/test_decorator_compat.py

@@ -172,6 +172,17 @@ async def starter(client: df.DurableFunctionsClient):
     assert await fb._function._func(client="{}") == "DurableFunctionsClient"
 
 
+async def test_durable_client_input_replaces_unsupported_client_annotation():
+    app = df.DFApp()
+
+    async def starter(client: int):
+        return type(client).__name__
+
+    fb = app.durable_client_input(client_name="client")(starter)
+    assert fb._function._func.__annotations__["client"] is str
+    assert starter.__annotations__["client"] is int
+
+
 # ---------------------------------------------------------------------------
 # All decorators register a function builder
 # ---------------------------------------------------------------------------