feat: determine version from vcs

The `hatch-vcs` is an extension to hatch's build system which
automatically determines the current version of the project based on the
VCS (i.e., git in this instance).

Specifically, it looks for the latest `vX.Y.Z` tag and:

- If the current `HEAD` is identical to the tag, sets a nice 'clean'
  version;
- If the current `HEAD` is infront of the tag, uses a dev build
  versioning of the form `vX.Y.Z.devN` where `N` is the number of
  commits between `HEAD` and the tag.

Signed-off-by: JP-Ellis <josh@jpellis.me>

Author: JP-Ellis

.gitignore

@@ -4,6 +4,9 @@
 pact/bin
 pact/data
 
+# Version is determined from the VCS
+pact/__version__.py
+
 ################################################################################
 ## Standard Templates
 ################################################################################

pact/__init__.py

@@ -9,8 +9,27 @@
 from .provider import Provider
 from .verifier import Verifier
 
-from .__version__ import __version__  # noqa: F401
+from .__version__ import __version__, __version_tuple__
 
-__all__ = ('Broker', 'Consumer', 'EachLike', 'Like',
-           'MessageConsumer', 'MessagePact', 'MessageProvider',
-           'Pact', 'Provider', 'SomethingLike', 'Term', 'Format', 'Verifier')
+__url__ = "https://github.com/pactflow/accord"
+__license__ = "MIT"
+
+__all__ = [
+    '__version__',
+    '__version_tuple__',
+    '__url__',
+    '__license__',
+    'Broker',
+    'Consumer',
+    'EachLike',
+    'Like',
+    'MessageConsumer',
+    'MessagePact',
+    'MessageProvider',
+    'Pact',
+    'Provider',
+    'SomethingLike',
+    'Term',
+    'Format',
+    'Verifier',
+]

pact/__version__.py

@@ -84,16 +84,20 @@ dev = ["pact-python[types]", "pact-python[test]", "ruff==0.2.2"]
 
 [build-system]
 requires = [
+  "cffi",
+  "hatch-vcs",
   "hatchling",
   "packaging",
   "requests",
-  "cffi",
   "setuptools ; python_version >= '3.12'",
 ]
 build-backend = "hatchling.build"
 
 [tool.hatch.version]
-path = "pact/__version__.py"
+source = "vcs"
+
+[tool.hatch.build.hooks.vcs]
+version-file = "pact/__version__.py"
 
 [tool.hatch.build]
 include = ["**/py.typed", "**/*.md", "LICENSE", "pact/**/*.py", "pact/**/*.pyi"]