Python: fix tool call content not showing up in workflow events (#1290)

* fix tool call content not showing up in workflow events

* fix lint

* touch up

* add another sample to show function bridge

* missing sample

python/packages/core/tests/workflow/test_agent_executor_tool_calls.py

@@ -0,0 +1,122 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+"""Tests for AgentExecutor handling of tool calls and results in streaming mode."""
+
+from collections.abc import AsyncIterable
+from typing import Any
+
+from agent_framework import (
+    AgentExecutor,
+    AgentRunResponse,
+    AgentRunResponseUpdate,
+    AgentRunUpdateEvent,
+    AgentThread,
+    BaseAgent,
+    ChatMessage,
+    FunctionCallContent,
+    FunctionResultContent,
+    Role,
+    TextContent,
+    WorkflowBuilder,
+)
+
+
+class _ToolCallingAgent(BaseAgent):
+    """Mock agent that simulates tool calls and results in streaming mode."""
+
+    def __init__(self, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+
+    async def run(
+        self,
+        messages: str | ChatMessage | list[str] | list[ChatMessage] | None = None,
+        *,
+        thread: AgentThread | None = None,
+        **kwargs: Any,
+    ) -> AgentRunResponse:
+        """Non-streaming run - not used in this test."""
+        return AgentRunResponse(messages=[ChatMessage(role=Role.ASSISTANT, text="done")])
+
+    async def run_stream(
+        self,
+        messages: str | ChatMessage | list[str] | list[ChatMessage] | None = None,
+        *,
+        thread: AgentThread | None = None,
+        **kwargs: Any,
+    ) -> AsyncIterable[AgentRunResponseUpdate]:
+        """Simulate streaming with tool calls and results."""
+        # First update: some text
+        yield AgentRunResponseUpdate(
+            contents=[TextContent(text="Let me search for that...")],
+            role=Role.ASSISTANT,
+        )
+
+        # Second update: tool call (no text!)
+        yield AgentRunResponseUpdate(
+            contents=[
+                FunctionCallContent(
+                    call_id="call_123",
+                    name="search",
+                    arguments={"query": "weather"},
+                )
+            ],
+            role=Role.ASSISTANT,
+        )
+
+        # Third update: tool result (no text!)
+        yield AgentRunResponseUpdate(
+            contents=[
+                FunctionResultContent(
+                    call_id="call_123",
+                    result={"temperature": 72, "condition": "sunny"},
+                )
+            ],
+            role=Role.TOOL,
+        )
+
+        # Fourth update: final text response
+        yield AgentRunResponseUpdate(
+            contents=[TextContent(text="The weather is sunny, 72°F.")],
+            role=Role.ASSISTANT,
+        )
+
+
+async def test_agent_executor_emits_tool_calls_in_streaming_mode() -> None:
+    """Test that AgentExecutor emits updates containing FunctionCallContent and FunctionResultContent."""
+    # Arrange
+    agent = _ToolCallingAgent(id="tool_agent", name="ToolAgent")
+    agent_exec = AgentExecutor(agent, id="tool_exec")
+
+    workflow = WorkflowBuilder().set_start_executor(agent_exec).build()
+
+    # Act: run in streaming mode
+    events: list[AgentRunUpdateEvent] = []
+    async for event in workflow.run_stream("What's the weather?"):
+        if isinstance(event, AgentRunUpdateEvent):
+            events.append(event)
+
+    # Assert: we should receive 4 events (text, function call, function result, text)
+    assert len(events) == 4, f"Expected 4 events, got {len(events)}"
+
+    # First event: text update
+    assert events[0].data is not None
+    assert isinstance(events[0].data.contents[0], TextContent)
+    assert "Let me search" in events[0].data.contents[0].text
+
+    # Second event: function call
+    assert events[1].data is not None
+    assert isinstance(events[1].data.contents[0], FunctionCallContent)
+    func_call = events[1].data.contents[0]
+    assert func_call.call_id == "call_123"
+    assert func_call.name == "search"
+
+    # Third event: function result
+    assert events[2].data is not None
+    assert isinstance(events[2].data.contents[0], FunctionResultContent)
+    func_result = events[2].data.contents[0]
+    assert func_result.call_id == "call_123"
+
+    # Fourth event: final text
+    assert events[3].data is not None
+    assert isinstance(events[3].data.contents[0], TextContent)
+    assert "sunny" in events[3].data.contents[0].text