Add check for dangling hyphens

[hugovk]

Fixes #54.

The failures are caused by finding IRL trailing hyphens in friend projects: pandas, cpython, peps, sympy.

E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/pandas/doc/source/ecosystem.rst:380: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/pandas/doc/source/user_guide/integer_na.rst:61: Line ends with dangling hyphen (dangling-hyphen)

E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/cpython/Doc/library/collections.rst:641: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/cpython/Doc/library/decimal.rst:295: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/cpython/Doc/library/decimal.rst:327: Line ends with dangling hyphen (dangling-hyphen)

E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/peps/pep-0560.rst:283: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/peps/pep-0554.rst:1274: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/peps/pep-0633.rst:119: Line ends with dangling hyphen (dangling-hyphen)

E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/sympy/doc/src/contributing/docstring.rst:50: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/sympy/doc/src/contributing/docstring.rst:741: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/vector/coordsys.rst:119: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/vector/coordsys.rst:217: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/combinatorics/fp_groups.rst:7: Line ends with dangling hyphen (dangling-hyphen)

---

Some false positives in there, such as:

E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/cpython/Doc/library/decimal.rst:295: Line ends with dangling hyphen (dangling-hyphen)
E         + /home/runner/work/sphinx-lint/sphinx-lint/tests/fixtures/friends/cpython/Doc/library/decimal.rst:327: Line ends with dangling hyphen (dangling-hyphen)

Both are inside .. doctest:: blocks:

https://github.com/python/cpython/blob/a35fd38b57d3eb05074ca36f3d57e1993c44ddc9/Doc/library/decimal.rst?plain=1#L295
https://github.com/python/cpython/blob/a35fd38b57d3eb05074ca36f3d57e1993c44ddc9/Doc/library/decimal.rst?plain=1#L327

We're using rst_only=True in the check to skip things like code blocks, but we're detecting doctest blocks as non-code. So let's fix that too.

---

Also, on macOS, I get failures like this, due to the annoying habit of macOS to create .DS_Store files, so let's skip them:

tests/test_xpass_friends.py:30:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/pathlib.py:1058: in read_text
    with self.open(mode='r', encoding=encoding, errors=errors) as f:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = PosixPath('/Users/huvankem/github/sphinx-lint/tests/fixtures/friends/.DS_Store/flags'), mode = 'r', buffering = -1, encoding = 'UTF-8'
errors = None, newline = None

    def open(self, mode='r', buffering=-1, encoding=None,
             errors=None, newline=None):
        """
        Open the file pointed by this path and return a file object, as
        the built-in open() function does.
        """
        if "b" not in mode:
            encoding = io.text_encoding(encoding)
>       return io.open(self, mode, buffering, encoding, errors, newline)
E       NotADirectoryError: [Errno 20] Not a directory: '/Users/huvankem/github/sphinx-lint/tests/fixtures/friends/.DS_Store/flags'

/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/pathlib.py:1044: NotADirectoryError

---

That leaves:

E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/sympy/doc/src/contributing/docstring.rst:50: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/sympy/doc/src/contributing/docstring.rst:741: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/combinatorics/fp_groups.rst:7: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/vector/coordsys.rst:119: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/sympy/doc/src/modules/vector/coordsys.rst:217: Line ends with dangling hyphen (dangling-hyphen)

E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/peps/pep-0554.rst:1274: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/peps/pep-0633.rst:119: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/peps/pep-0560.rst:283: Line ends with dangling hyphen (dangling-hyphen)

E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/pandas/doc/source/ecosystem.rst:380: Line ends with dangling hyphen (dangling-hyphen)
E         + /Users/huvankem/github/sphinx-lint/tests/fixtures/friends/pandas/doc/source/user_guide/integer_na.rst:61: Line ends with dangling hyphen (dangling-hyphen)

These are valid, except these use hyphens like colons:

https://github.com/sympy/sympy/blob/5d2556f1546b1fe64e175fa808f495a58c3ac998/doc/src/modules/vector/coordsys.rst?plain=1#L119

https://github.com/sympy/sympy/blob/5d2556f1546b1fe64e175fa808f495a58c3ac998/doc/src/modules/vector/coordsys.rst?plain=1#L217

---

How should we deal with the failing "friend" tests?

[JelleZijlstra]

Thanks! Perhaps the sympy ones could be considered true positives; it's not grammatical to use a hyphen there. Alternatively, perhaps we could exclude lines right before a blank line from the check.

[hugovk]

Thanks! Perhaps the sympy ones could be considered true positives; it's not grammatical to use a hyphen there. Alternatively, perhaps we could exclude lines right before a blank line from the check.

Yeah, I'd prefer a colon there too.

[JulienPalard]

Thanks a lot of this PR!

Let's fix friend projects and merge it! (Better not merge it before, it could break their CI if they did not pinned the sphinx-lint version).

[hugovk]

Thanks for fixing the friend projects! This CI is now passing: https://github.com/hugovk/sphinx-lint/actions/runs/4393071119

[JulienPalard]

Thanks for this PR!