Public API for `DoctestItem`

[tony]

I assume by DoctestItem only being available from _pytest.doctest.DoctestItem, it's an internal / unstable API.

If I'm completely mistaken in that assumption please let me know

What's the problem this feature will solve?

Stable import for:

• isinstance checking inside of autorun setup fixtures w/ doctest_namespace (see my libtmux, libvcs examples, as well and cs.github.com search query)
• other plugins re-using DoctestItem, e.g. my docutils plugin

Describe the solution you'd like

Perhaps pytest.DoctestItem or something of the sort

Alternative Solutions

Further battle-testing of pytest's doctest plugin to stabilize the API, then exporting it

Additional context

I am using DoctestItem on 3+ open source projects and need a stable place to import the type from

1. libtmux/conftest.py
2. libvcs/src/libvcs/conftest.py
3. pytest-doctest-docutils (overrides pytest's doctest plugin)
4. See search for /from.*DoctestItem/ language:Python on cs.github.com

[nicoddemus]

Hi @tony,

I think we could make DoctestItem public for type annotation purposes, but other than that we should also make all its methods private to discourage users from subclassing/calling any public methods on it.

[tony]

@nicoddemus Thank you for looking into this

PR created at #10313

but other than that we should also make all its methods private to discourage users from subclassing/calling any public methods on it.

It looks like the methods in DoctestItem are from Item / Node, I suppose those are to be expected?