Add custom callback exception callable

[ahuang11]

Closes #6047

[philippjfr]

Can you add entries in CHANGELOG.md and doc/releases.md?

[codecov]

Codecov Report

Attention: Patch coverage is 70.58824% with 5 lines in your changes missing coverage. Please review.

Project coverage is 41.63%. Comparing base (55b0634) to head (3b160b8).

Files with missing lines	Patch %	Lines
panel/chat/feed.py	33.33%	4 Missing ⚠️
panel/chat/_param.py	90.90%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #7558       +/-   ##
===========================================
- Coverage   81.38%   41.63%   -39.75%     
===========================================
  Files         340      329       -11     
  Lines       51487    49172     -2315     
===========================================
- Hits        41902    20474    -21428     
- Misses       9585    28698    +19113     

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[ahuang11]

Is this a bug with param?
chat_feed.callback_exception = exception_callback

panel/tests/chat/test_feed.py

Traceback (most recent call last):
  File "/Users/ahuang/repos/panel/panel/tests/chat/test_feed.py", line 1134, in test_callback_exception_async_callable
    chat_feed.callback_exception = exception_callback
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 528, in _f
    instance_param.__set__(obj, val)
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 530, in _f
    return f(self, obj, val)
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 1476, in __set__
    ref, deps, val, is_async = obj.param._resolve_ref(self, val)
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 2044, in _resolve_ref
    value = resolve_value(value, recursive=pobj.nested_refs)
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 186, in resolve_value
    value = eval_function_with_deps(value)
  File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/site-packages/param/parameterized.py", line 165, in eval_function_with_deps
    return function(*args, **kwargs)
TypeError: TestChatFeedCallback.test_callback_exception_async_callable.<locals>.exception_callback() missing 2 required positional arguments: 'exception' and 'instance'

If it's sync, it raises so I added a ignore, but I don't think it should be ignored:

===================================================================================================== FAILURES =====================================================================================================
______________________________________________________________________________ TestChatFeedCallback.test_callback_exception_callable _______________________________________________________________________________

cls = <class '_pytest.runner.CallInfo'>, func = <function call_and_report.<locals>.<lambda> at 0x16a7067a0>, when = 'call', reraise = (<class '_pytest.outcomes.Exit'>, <class 'KeyboardInterrupt'>)

    @classmethod
    def from_call(
        cls,
        func: Callable[[], TResult],
        when: Literal["collect", "setup", "call", "teardown"],
        reraise: type[BaseException] | tuple[type[BaseException], ...] | None = None,
    ) -> CallInfo[TResult]:
        """Call func, wrapping the result in a CallInfo.

        :param func:
            The function to call. Called without arguments.
        :type func: Callable[[], _pytest.runner.TResult]
        :param when:
            The phase in which the function is called.
        :param reraise:
            Exception or exceptions that shall propagate if raised by the
            function, instead of being wrapped in the CallInfo.
        """
        excinfo = None
        start = timing.time()
        precise_start = timing.perf_counter()
        try:
>           result: TResult | None = func()

../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/runner.py:341:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/runner.py:242: in <lambda>
    lambda: runtest_hook(item=item, **kwds), when=when, reraise=reraise
../../miniconda3/envs/panel/lib/python3.10/site-packages/pluggy/_hooks.py:513: in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
../../miniconda3/envs/panel/lib/python3.10/site-packages/pluggy/_manager.py:120: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/threadexception.py:92: in pytest_runtest_call
    yield from thread_exception_runtest_hook()
../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/threadexception.py:68: in thread_exception_runtest_hook
    yield
../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/unraisableexception.py:95: in pytest_runtest_call
    yield from unraisable_exception_runtest_hook()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

    def unraisable_exception_runtest_hook() -> Generator[None]:
        with catch_unraisable_exception() as cm:
            try:
                yield
            finally:
                if cm.unraisable:
                    if cm.unraisable.err_msg is not None:
                        err_msg = cm.unraisable.err_msg
                    else:
                        err_msg = "Exception ignored in"
                    msg = f"{err_msg}: {cm.unraisable.object!r}\n\n"
                    msg += "".join(
                        traceback.format_exception(
                            cm.unraisable.exc_type,
                            cm.unraisable.exc_value,
                            cm.unraisable.exc_traceback,
                        )
                    )
>                   warnings.warn(pytest.PytestUnraisableExceptionWarning(msg))
E                   pytest.PytestUnraisableExceptionWarning: Exception ignored in: <socket.socket fd=-1, family=AddressFamily.AF_UNIX, type=SocketKind.SOCK_STREAM, proto=0>
E
E                   Traceback (most recent call last):
E                     File "/Users/ahuang/miniconda3/envs/panel/lib/python3.10/asyncio/base_events.py", line 773, in _call_soon
E                       handle = events.Handle(callback, args, self, context)
E                   ResourceWarning: unclosed <socket.socket fd=16, family=AddressFamily.AF_UNIX, type=SocketKind.SOCK_STREAM, proto=0>

../../miniconda3/envs/panel/lib/python3.10/site-packages/_pytest/unraisableexception.py:85: PytestUnraisableExceptionWarning
============================================================================================= short test summary info ==============================================================================================
FAILED panel/tests/chat/test_feed.py::TestChatFeedCallback::test_callback_exception_callable - pytest.PytestUnraisableExceptionWarning: Exception ignored in: <socket.socket fd=-1, family=AddressFamily.AF_UNIX, type=SocketKind.SOCK_STREAM, proto=0>