Make einfo compatible with inspect (fixes #176)

[mrcljx]

Libraries like sentry or better-exceptions will fail while traversing exception chains with getframeinfo like this:

AttributeError: 'Traceback' object has no attribute 'f_lineno'

As mentioned in #176, we can not inherit from types.Traceback and friends, but it's possible to override __class__ which will make the isinstance check pass. This is also used internally by Python's unittest.mock module.

    @property
    def __class__(self):
        if self._spec_class is None:
            return type(self)
        return self._spec_class

An alternative approach could be to use a meta class and implement __subclasscheck__ ¹, but that felt too involved.

Footnotes

1. https://docs.python.org/3/reference/datamodel.html#class.__subclasscheck__ ↩

[auvipy]

please check the test failures in the CI

[auvipy]

can you please rebase?

[auvipy]

we will need to fix the CI first

[Copilot]

Pull request overview

This PR makes the custom traceback, frame, and code classes in billiard compatible with Python's inspect module by overriding the __class__ property to return the corresponding native types. This fixes issue #176 where libraries like Sentry and better-exceptions fail when trying to use inspect.getinnerframes() and similar functions on billiard's custom traceback objects.

Changes:

• Added __class__ property overrides to _Code, _Frame, _Truncated, and Traceback classes to return their corresponding types module counterparts
• Added comprehensive test suite for inspect module compatibility, including tests for istraceback, isframe, iscode, getframeinfo, and getinnerframes
• Added helper function make_python_tb() to create test traceback objects

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 5 comments.

File	Description
billiard/einfo.py	Added __class__ property overrides to _Code, _Frame, _Truncated, and Traceback classes to make them compatible with isinstance checks in the inspect module
t/unit/test_einfo.py	Added new test class test_inspect with tests for inspect module functions, and added helper function make_python_tb() to generate test tracebacks

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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[auvipy]

thanks for fixing the CI. and please do not force push for easier review and diff.

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

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