Compatibility with setuptools_scm 7

[frenzymadness]

I'm testing hatch-vcs with the latest setuptools_scm and one test fails:

============================= test session starts ==============================
platform linux -- Python 3.11.0b3, pytest-7.1.2, pluggy-1.0.0
rootdir: /builddir/build/BUILD/hatch_vcs-0.2.0
collected 16 items

tests/test_build.py .F.                                                  [ 18%]
tests/test_build_config.py ......                                        [ 56%]
tests/test_version_config.py .......                                     [100%]

=================================== FAILURES ===================================
__________________________________ test_write __________________________________

new_project_write = '/tmp/tmpbb8uz4_h/my-app'

    def test_write(new_project_write):
        build_project('-t', 'wheel')
    
        build_dir = os.path.join(new_project_write, 'dist')
        assert os.path.isdir(build_dir)
    
        artifacts = os.listdir(build_dir)
        assert len(artifacts) == 1
        wheel_file = artifacts[0]
    
        assert wheel_file == 'my_app-1.2.3-py2.py3-none-any.whl'
    
        extraction_directory = os.path.join(os.path.dirname(new_project_write), '_archive')
        os.mkdir(extraction_directory)
    
        with zipfile.ZipFile(os.path.join(build_dir, wheel_file), 'r') as zip_archive:
            zip_archive.extractall(extraction_directory)
    
        metadata_directory = os.path.join(extraction_directory, 'my_app-1.2.3.dist-info')
        assert os.path.isdir(metadata_directory)
    
        package_directory = os.path.join(extraction_directory, 'my_app')
        assert os.path.isdir(package_directory)
        assert len(os.listdir(package_directory)) == 5
    
        assert os.path.isfile(os.path.join(package_directory, '__init__.py'))
        assert os.path.isfile(os.path.join(package_directory, 'foo.py'))
        assert os.path.isfile(os.path.join(package_directory, 'bar.py'))
        assert os.path.isfile(os.path.join(package_directory, 'baz.py'))
    
        version_file = os.path.join(package_directory, '_version.py')
        assert os.path.isfile(version_file)
    
        lines = read_file(version_file).splitlines()
>       assert lines[3] == "version = '1.2.3'"
E       assert "__version__ ...ion = '1.2.3'" == "version = '1.2.3'"
E         - version = '1.2.3'
E         + __version__ = version = '1.2.3'

/builddir/build/BUILD/hatch_vcs-0.2.0/tests/test_build.py:78: AssertionError
=========================== short test summary info ============================
FAILED tests/test_build.py::test_write - assert "__version__ ...ion = '1.2.3'...
========================= 1 failed, 15 passed in 0.87s =========================

[frenzymadness]

The failure is caused by this change: pypa/setuptools-scm@b45e19f#diff-bdefa0298003efada7c465428643cc6d9c129168afb3eb5c551b40fcc77feac1

We can either check that the line[3] ends with version = '1.2.3' or we can check the exact content of the line for setuptools_scm <7 and >=7. But I'm not sure that there is an easy way to get the version of setuptools_scm itself so we might need to use importlib_metadata for this and it might not be perfect.

What do you prefer?

[frenzymadness]

@RonnyPfannschmidt is there any simple way to get the version of setuptools_scm? Something like setuptools_scm.__version__.

[RonnyPfannschmidt]

@frenzymadness asking importlib metadata is the intended way at the moment,

i think i should add a version attribute thats lazily computed

[musicinmybrain]

@frenzymadness, thank you for diagnosing and fixing this. I will go ahead and apply your PR in the Fedora package for now to unblock your setuptools_scm testing.

@ofek, do you prefer the approach in #9, or do you prefer to write something like

assert lines[3].endswith("version = '1.2.3'")

to accommodate both older and newer setuptools_scm versions?

[ofek]

I prefer ^ quick fix b/c I plan to switch to https://hatch.pypa.io/dev/plugins/build-hook/version/