Prerelease version strings such as 1.0.0-rc1 were incorrectly returned as 1.0.0rc1 (without dash) because of an issue with setuptools_scm due to pkg_resources removing the dash of prerelease versions. Fixes #10

Author: Sylvain MARIE

getversion/plugin_setuptools_scm.py

@@ -27,9 +27,54 @@ def __str__(self):
 
 try:
     from setuptools_scm import get_version
+    from setuptools_scm.version import guess_next_dev_version
     from setuptools_scm.utils import has_command
     has_git_command = has_command('git')
 
+
+    def fixed_version_scheme(version):
+        """
+        A fix for https://github.com/smarie/python-getversion/issues/10
+        until this is fixed in setuptools_scm or in pkg_resources
+        so that the dash is not removed when a pre-release version is present (e.g. 1.0.0-rc1)
+        """
+        # This is the bugged string would be used by the default scheme (for reference)
+        # str(version.tag)
+
+        # modify the 'pre' part only if needed
+        do_hack = version.tag.is_prerelease
+        if do_hack:
+            # make a backup
+            _version_bak = version.tag._version
+
+            # get the various parts
+            parts = _version_bak._asdict()
+
+            # make sure we understand what we do by doing a simple copy
+            clone = type(_version_bak)(**parts)
+            assert clone == _version_bak, "Internal error with this version of `pkg_resources`, please report"
+
+            # now do a mod
+            parts['pre'] = ("-",) + parts['pre']
+            _version_mod = type(_version_bak)(**parts)
+
+            # and apply it
+            version.tag._version = _version_mod
+
+            # we can check that the string has been fixed correctly
+            # str(version.tag)
+
+        # create the version string as usual by applying setuptools_scm's default version scheme
+        # note that despite the name, this does not increment anything if the tag is exact (no local mod)
+        res = guess_next_dev_version(version)
+
+        # undo our hack if needed
+        if do_hack:
+            version.tag._version = _version_bak  # noqa
+
+        return res
+
+
     def scm_get_version_recursive_root(abs_path, initial_path):
         """
         Recursively climbs the parent folders, searching for a git root
@@ -38,7 +83,7 @@ def scm_get_version_recursive_root(abs_path, initial_path):
         :return:
         """
         try:
-            return get_version(abs_path)
+            res = get_version(abs_path, version_scheme=fixed_version_scheme)
         except LookupError as e:
             parent_dir = dirname(abs_path)
             if parent_dir == abs_path:
@@ -47,7 +92,8 @@ def scm_get_version_recursive_root(abs_path, initial_path):
             else:
                 # recurse
                 return scm_get_version_recursive_root(parent_dir, initial_path=initial_path)
-
+        else:
+            return res
 
     def get_version_using_setuptools_scm(module  # type: ModuleType
                                          ):

getversion/tests/test_issues.py

@@ -0,0 +1,40 @@
+from os.path import join, pardir
+
+from setuptools_scm import _do_parse, Configuration, format_version
+from getversion.plugin_setuptools_scm import fixed_version_scheme
+
+from pkg_resources import parse_version as pkg_parse_version
+
+
+def test_issue_10():
+    # version with a prerelease
+    version_str = "1.0.0-rc1"
+
+    # Parse with pkg_resource and make sure that the issue is still there (see #10)
+    pkg_res_version = pkg_parse_version(version_str)
+    assert str(pkg_res_version) == '1.0.0rc1'
+
+    # use setuptools_scm to get a version object that we can modify to introduce the bug
+    config = Configuration(root=join(__file__, pardir, pardir, pardir))
+    s_version = _do_parse(config)
+    # --make sure that internals of `setuptools_scm` have not changed: the .tag object is a pkg_resource Version
+    assert isinstance(s_version.tag, type(pkg_res_version))
+    # --now lets modify the version object so as to inject the issue
+    s_version.tag = pkg_res_version
+
+    # make sure that setuptools_scm did not fix the issue yet
+    pb_ver = format_version(
+        s_version,
+        version_scheme=config.version_scheme,
+        local_scheme=config.local_scheme,
+    )
+    assert str(pb_ver) != version_str
+    assert str(pb_ver).startswith("1.0.0rc")  # dash removed
+
+    # make sure that with our fixed version scheme (used in our plugin) it works
+    fixed_vers = format_version(
+        s_version,
+        version_scheme=fixed_version_scheme,
+        local_scheme=config.local_scheme,
+    )
+    assert str(fixed_vers).startswith("1.0.0-rc")  # with the dash