Allow cancel out of the streaming result

[handrew]

Fix for #574

@rm-openai I'm not sure how to add a test within the repo but I have pasted a test script below that seems to work

import asyncio
from openai.types.responses import ResponseTextDeltaEvent
from agents import Agent, Runner

async def main():
    agent = Agent(
        name="Joker",
        instructions="You are a helpful assistant.",
    )

    result = Runner.run_streamed(agent, input="Please tell me 5 jokes.")
    num_visible_event = 0
    async for event in result.stream_events():
        if event.type == "raw_response_event" and isinstance(event.data, ResponseTextDeltaEvent):
            print(event.data.delta, end="", flush=True)
            num_visible_event += 1
            print(num_visible_event)
            if num_visible_event == 3:
                result.cancel()


if __name__ == "__main__":
    asyncio.run(main())

[rm-openai]

@handrew looks good! You can add unit tests to the tests/ directory. If you use codex/cursor/windsurf/chatgpt, they can suggest tests and probably even help you write them. You can run the tests locally via make tests

[rm-openai]

is this necessary? cleanup still occurs outside of the loop

[handrew]

I suppose not, though the AI thought it was 😅

[handrew]

Removed this

[handrew]

Thanks for the tip @rm-openai , I'll be sure to do that in the future, pretty neat. Anyway, added the test!

[rm-openai]

@handrew Test looks good, but it doesn't look like the test is passing - seems like its an infinite loop. You may need to use FakeModel, since there's no network access in unit tests.

Also lint is failing - could you fix plz?

[handrew]

@handrew Test looks good, but it doesn't look like the test is passing - seems like its an infinite loop. You may need to use FakeModel, since there's no network access in unit tests.

Also lint is failing - could you fix plz?

Used FakeModel, good call. It only yields two events so I test cancelling after one. Also linted.

Thanks @rm-openai , this was fun. Any idea when I might be able to --upgrade and get this fix :)?

[rm-openai]

@handrew I'm merging the PR now. Will probably cut a new release tomorrow morning, so should be able to upgrade then.

You can also temporarily directly install from the latest code in this repo if you want, which will include your change

pip uninstall openai-agents
pip install git+https://github.com/openai/openai-agents-python.git