move logic of _commit_distance_version() to shore.utils.version module, it now returns None if the commit distance is 0, _commit_distance_version() now delegates to get_commit_distance_version() and returns the original version unchanged if the commit distance is 0, also adds ".dirty" if the working state is dirty

src/shore/__main__.py

@@ -36,7 +36,7 @@ from shore.util import git as _git
 from shore.util.classifiers import get_classifiers
 from shore.util.license import get_license_metadata, wrap_license_text
 from shore.util.resources import walk_package_resources
-from shore.util.version import parse_version, bump_version, Version
+from shore.util.version import get_commit_distance_version, parse_version, bump_version, Version
 from termcolor import colored
 from typing import Any, Dict, Iterable, List, Optional, Union
 import click
@@ -65,43 +65,13 @@ def _get_author_info_from_git():
 
 
 def _commit_distance_version(subject: [Monorepo, Package]) -> Version:
-  """ This function creates a string which describes the version of the
-  monorepo or package that includes the commit distance and SHA revision
-  number.
-
-  For a mono repository, the full commit distance is used. The same is true
-  for a single package. For a package inside a mono repository that does not
-  apply mono versioning, the packages' local commit distance is used.
-
-  This is close to what `git describe --tags` does. An example version number
-  generated by this function is: `0.1.0-24-gd9ade3f`
-
-  Notes:
-
-  - The produced version string is not compatible with PEP440.
-  - If the tag for the version of *subject* does not exist on the repository,
-    it will fall back to 0.0.0 as the version number which is treated as
-    "the beginning of the repository", even if no tag for this version exists.
-
-    - Todo: We could try to find the previous tag for this subject and use
-      that.
-  """
-
   if isinstance(subject, Package) and subject.monorepo \
       and subject.monorepo.mono_versioning:
     subject = subject.monorepo
-
-  tag = subject.get_tag(subject.version)
-  if _git.rev_parse(tag):
-    version = subject.version
-    distance = len(_git.rev_list(tag + '..HEAD', subject.directory))
-  else:
-    logger.warning('tag "%s" does not exist', tag)
-    version = Version('0.0.0')
-    distance = len(_git.rev_list('HEAD', subject.directory))
-
-  rev = _git.rev_parse('HEAD')
-  return parse_version(str(version) + '+{}.g{}'.format(distance, rev[:7]))
+  return get_commit_distance_version(
+    subject.directory,
+    subject.version,
+    subject.get_tag(subject.version)) or subject.version
 
 
 def _load_subject() -> Union[Monorepo, Package, None]:
@@ -611,12 +581,12 @@ def status():
 
 @cli.command()
 @click.option('--tag', '-t', is_flag=True)
-@click.option('--git', '-g', is_flag=True)
-def version(git, tag):
+@click.option('--snapshot', '-s', is_flag=True)
+def version(tag, snapshot):
   """ Print the current package or repository version. """
 
   subject = _load_subject()
-  version = _commit_distance_version(subject) if git else subject.version
+  version = _commit_distance_version(subject) if snapshot else subject.version
   if tag:
     print(subject.get_tag(version))
   else:

src/shore/util/git.py

@@ -78,10 +78,10 @@ def tag(tag_name: str, force: bool=False):
   subprocess.check_call(command)
 
 
-def rev_parse(rev: str) -> Optional[str]:
+def rev_parse(rev: str, path: str = None) -> Optional[str]:
   command = ['git', 'rev-parse', rev]
   try:
-    return subprocess.check_output(command, stderr=subprocess.STDOUT).decode().strip()
+    return subprocess.check_output(command, stderr=subprocess.STDOUT, cwd=path).decode().strip()
   except subprocess.CalledProcessError:
     return None
 
@@ -94,3 +94,13 @@ def rev_list(rev: str, path: str = None) -> List[str]:
   if revlist == ['']:
     revlist = []
   return revlist
+
+
+def has_diff(path: str = None) -> bool:
+  try:
+    subprocess.check_call(['git', 'diff', '--exit-code'], stdout=subprocess.PIPE)
+    return False
+  except subprocess.CalledProcessError as exc:
+    if exc.returncode == 1:
+      return True
+    raise

src/shore/util/version.py

@@ -20,7 +20,8 @@
 # IN THE SOFTWARE.
 
 from packaging.version import Version as _Version
-from typing import Union
+from shore.util import git as _git
+from typing import Optional, Union
 import re
 
 
@@ -104,3 +105,48 @@ def bump_version(version: Version, kind: str) -> Version:
   if post:
     string += '.post' + str(post)
   return Version(string)
+
+
+def get_commit_distance_version(repo_dir: str, version: Version, latest_tag: str) -> Optional[Version]:
+  """
+  This function creates a string which describes the version of the
+  monorepo or package that includes the commit distance and SHA revision
+  number.
+
+  For a mono repository, the full commit distance is used. The same is true
+  for a single package. For a package inside a mono repository that does not
+  apply mono versioning, the packages' local commit distance is used.
+
+  This is close to what `git describe --tags` does. An example version number
+  generated by this function is: `0.1.0+24.gd9ade3f`. If the working state is
+  dirty, `.dirty` will be appended to the local version.
+
+  Notes:
+
+  - If there is no commit distance from the *latest_tag* to the current
+    state of the repository, this function returns None.
+  - The version returned by this function is a PEP440 local version that
+    cannot be used for packages when submitting them to PyPI.
+  - If the tag for the version of *subject* does not exist on the repository,
+    it will fall back to 0.0.0 as the version number which is treated as
+    "the beginning of the repository", even if no tag for this version exists.
+
+    Todo: We could try to find the previous tag for this subject and use that.
+  """
+
+  if _git.rev_parse(latest_tag):
+    distance = len(_git.rev_list(latest_tag + '..HEAD', repo_dir))
+  else:
+    logger.warning('tag "%s" does not exist', latest_tag)
+    version = Version('0.0.0')
+    distance = len(_git.rev_list('HEAD', repo_dir))
+
+  if distance == 0:
+    return None
+
+  suffix = ''
+  if _git.has_diff(repo_dir):
+    suffix = '.dirty'
+
+  rev = _git.rev_parse('HEAD', repo_dir)
+  return parse_version(str(version) + '+{}.g{}{}'.format(distance, rev[:7], suffix))