fix(browser): set event loop on calling thread before nest_asyncio.apply

[Hweinstock]

Description

Fix a bug in the browser tool that causes it to fail when invoked async. See issue for more information.

The solution is to verify that the event loop is set on the thread that executes the browser tool so that it doesn't matter what thread executes the tool.

Related Issues

Documentation PR

N/A

Type of Change

Bug fix

Testing

How have you tested the change? Verify that the changes do not break functionality or introduce warnings in consuming repositories: agents-docs, agents-tools, agents-cli

• I ran hatch run prepare

• Added a unit test to simulate the scenario.

• Patched the import in agent code using browser, and confirmed it works e2e.

patch code used:

loop = browser_instance._loop
original = browser_instance._execute_async

def _patched(coro):
   asyncio.set_event_loop(loop)
   return original(coro)
 
browser_instance._execute_async = _patched

which is effectively the underlying implementation.

Checklist

• I have read the CONTRIBUTING document
• I have added any necessary tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature
• My changes generate no new warnings
• Any dependent changes have been merged and published

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