Fix serialization error in curl api (#9189)

* Fix code

* add changeset

* Fix code

* fix

* add another test

---------

Co-authored-by: gradio-pr-bot <gradio-pr-bot@users.noreply.github.com>
Co-authored-by: Abubakar Abid <abubakar@huggingface.co>

.changeset/moody-dogs-search.md

@@ -0,0 +1,5 @@
+---
+"gradio": patch
+---
+
+fix:Fix serialization error in curl api

gradio/routes.py

@@ -891,12 +891,13 @@ class App(FastAPI):
             event_id: str,
         ):
             def process_msg(message: EventMessage) -> str | None:
+                msg = message.model_dump()
                 if isinstance(message, ProcessCompletedMessage):
                     event = "complete" if message.success else "error"
-                    data = message.output.get("data")
+                    data = msg["output"].get("data")
                 elif isinstance(message, ProcessGeneratingMessage):
                     event = "generating" if message.success else "error"
-                    data = message.output.get("data")
+                    data = msg["output"].get("data")
                 elif isinstance(message, HeartbeatMessage):
                     event = "heartbeat"
                     data = None

test/test_routes.py

@@ -1,6 +1,7 @@
 """Contains tests for networking.py and app.py"""
 
 import functools
+import json
 import os
 import pickle
 import tempfile
@@ -1454,3 +1455,35 @@ def test_file_access():
         demo.close()
         not_allowed_file.unlink()
         allowed_file.unlink()
+
+
+def test_bash_api_serialization():
+    demo = gr.Interface(lambda x: x, "json", "json")
+
+    app, _, _ = demo.launch(prevent_thread_lock=True)
+    test_client = TestClient(app)
+
+    with test_client:
+        submit = test_client.post("/call/predict", json={"data": [{"a": 1}]})
+        event_id = submit.json()["event_id"]
+        response = test_client.get(f"/call/predict/{event_id}")
+        assert response.status_code == 200
+        assert "event: complete\ndata:" in response.text
+        assert json.dumps({"a": 1}) in response.text
+
+
+def test_bash_api_multiple_inputs_outputs():
+    demo = gr.Interface(
+        lambda x, y: (y, x), ["textbox", "number"], ["number", "textbox"]
+    )
+
+    app, _, _ = demo.launch(prevent_thread_lock=True)
+    test_client = TestClient(app)
+
+    with test_client:
+        submit = test_client.post("/call/predict", json={"data": ["abc", 123]})
+        event_id = submit.json()["event_id"]
+        response = test_client.get(f"/call/predict/{event_id}")
+        assert response.status_code == 200
+        assert "event: complete\ndata:" in response.text
+        assert json.dumps([123, "abc"]) in response.text