Add a test for output type coercion (#1076)

* Add a test for output type coercion

* remove prints

Author: tconley1428

tests/contrib/openai_agents/test_openai.py

@@ -8,6 +8,7 @@
 from typing import Any, AsyncIterator, Optional, Union, no_type_check
 
 import nexusrpc
+import pydantic
 import pytest
 from agents import (
     Agent,
@@ -2221,3 +2222,59 @@ def provide(
         async for e in workflow_handle.fetch_history_events():
             if e.HasField("activity_task_scheduled_event_attributes"):
                 assert e.user_metadata.summary.data == b'"My summary"'
+
+
+class OutputType(pydantic.BaseModel):
+    answer: str
+    model_config = ConfigDict(extra="forbid")  # Forbid additional properties
+
+
+@workflow.defn
+class OutputTypeWorkflow:
+    @workflow.run
+    async def run(self) -> OutputType:
+        agent: Agent = Agent(
+            name="Assistant",
+            instructions="You are a helpful assistant, adhere to the json schema output",
+            output_type=OutputType,
+        )
+        result = await Runner.run(
+            starting_agent=agent,
+            input="Hello!",
+        )
+        return result.final_output
+
+
+class OutputTypeModel(StaticTestModel):
+    responses = [
+        ResponseBuilders.output_message(
+            '{"answer": "My answer"}',
+        ),
+    ]
+
+
+async def test_output_type(client: Client):
+    new_config = client.config()
+    new_config["plugins"] = [
+        openai_agents.OpenAIAgentsPlugin(
+            model_params=ModelActivityParameters(
+                start_to_close_timeout=timedelta(seconds=120),
+            ),
+            model_provider=TestModelProvider(OutputTypeModel()),
+        )
+    ]
+    client = Client(**new_config)
+
+    async with new_worker(
+        client,
+        OutputTypeWorkflow,
+    ) as worker:
+        workflow_handle = await client.start_workflow(
+            OutputTypeWorkflow.run,
+            id=f"output-type-{uuid.uuid4()}",
+            task_queue=worker.task_queue,
+            execution_timeout=timedelta(seconds=10),
+        )
+        result = await workflow_handle.result()
+        assert isinstance(result, OutputType)
+        assert result.answer == "My answer"