De-flake Prefect test by enforcing sequential tool calls for test (#3177)

Author: desertaxle

tests/test_prefect.py

@@ -208,9 +208,11 @@ async def test_complex_agent_run_in_flow(allow_model_requests: None, capfire: Ca
 
     @flow(name='test_complex_agent_run_in_flow')
     async def run_complex_agent() -> Response:
-        result = await complex_prefect_agent.run(
-            'Tell me: the capital of the country; the weather there; the product name', deps=Deps(country='Mexico')
-        )
+        # Use sequential tool calls to avoid flaky test due to non-deterministic ordering
+        with Agent.sequential_tool_calls():
+            result = await complex_prefect_agent.run(
+                'Tell me: the capital of the country; the weather there; the product name', deps=Deps(country='Mexico')
+            )
         return result.output
 
     # Prefect sets the `traceparent` header, so we explicitly disable distributed tracing for the tests to avoid the warning,
@@ -364,9 +366,12 @@ async def run_complex_agent() -> Response:
                                     content='running 2 tools',
                                     children=[
                                         BasicSpan(
-                                            content='running tool: get_product_name',
+                                            content='running tool: get_weather',
                                             children=[
-                                                BasicSpan(content=IsStr(regex=r'Call MCP Tool: get_product_name-\w+'))
+                                                BasicSpan(
+                                                    content=IsStr(regex=r'Call Tool: get_weather-\w+'),
+                                                    children=[BasicSpan(content=IsStr(regex=r'get_weather-\w+'))],
+                                                )
                                             ],
                                         ),
                                         BasicSpan(
@@ -375,18 +380,15 @@ async def run_complex_agent() -> Response:
                                                 BasicSpan(content='ctx.run_step=2'),
                                                 BasicSpan(
                                                     content=IsStr(
-                                                        regex=r'\{"result":\{"tool_name":"get_product_name","content":"Pydantic AI","tool_call_id":"call_SkGkkGDvHQEEk0CGbnAh2AQw","metadata":null,"timestamp":"[^"]+","part_kind":"tool-return"\},"content":null,"event_kind":"function_tool_result"\}'
+                                                        regex=r'\{"result":\{"tool_name":"get_weather","content":"sunny","tool_call_id":"call_NS4iQj14cDFwc0BnrKqDHavt","metadata":null,"timestamp":"[^"]+","part_kind":"tool-return"\},"content":null,"event_kind":"function_tool_result"\}'
                                                     )
                                                 ),
                                             ],
                                         ),
                                         BasicSpan(
-                                            content='running tool: get_weather',
+                                            content='running tool: get_product_name',
                                             children=[
-                                                BasicSpan(
-                                                    content=IsStr(regex=r'Call Tool: get_weather-\w+'),
-                                                    children=[BasicSpan(content=IsStr(regex=r'get_weather-\w+'))],
-                                                )
+                                                BasicSpan(content=IsStr(regex=r'Call MCP Tool: get_product_name-\w+'))
                                             ],
                                         ),
                                         BasicSpan(
@@ -395,7 +397,7 @@ async def run_complex_agent() -> Response:
                                                 BasicSpan(content='ctx.run_step=2'),
                                                 BasicSpan(
                                                     content=IsStr(
-                                                        regex=r'\{"result":\{"tool_name":"get_weather","content":"sunny","tool_call_id":"call_NS4iQj14cDFwc0BnrKqDHavt","metadata":null,"timestamp":"[^"]+","part_kind":"tool-return"\},"content":null,"event_kind":"function_tool_result"\}'
+                                                        regex=r'\{"result":\{"tool_name":"get_product_name","content":"Pydantic AI","tool_call_id":"call_SkGkkGDvHQEEk0CGbnAh2AQw","metadata":null,"timestamp":"[^"]+","part_kind":"tool-return"\},"content":null,"event_kind":"function_tool_result"\}'
                                                     )
                                                 ),
                                             ],