store package version in __version__ constant (#117)

This allows using the `hatch version` tool to automatically update
versions and makes sure the version metadata of editable installs is
always up to date.

noxfile.py

@@ -125,17 +125,6 @@ def typing(session: nox.Session):
     )
 
 
-def _repl_version(session: nox.Session, new_version: str):
-    with open("pyproject.toml", "r+") as fp:
-        lines = tuple(fp)
-        fp.seek(0)
-        for line in lines:
-            if line.startswith("version = "):
-                line = f'version = "{new_version}"\n'
-            fp.write(line)
-        fp.truncate()
-
-
 def check_no_modifications(session: nox.Session) -> None:
     modified = session.run(
         "git",
@@ -192,7 +181,7 @@ def bump(session: nox.Session):
                 "or two positional arguments must be provided."
             )
     install(session, "antsibull-changelog[toml]", "hatch")
-    _repl_version(session, version)
+    session.run("hatch", "version", version)
     if len(session.posargs) > 1:
         fragment = session.run(
             "python",
@@ -203,18 +192,24 @@ def bump(session: nox.Session):
         )
         with open(fragment_file, "w") as fp:
             print(fragment, file=fp)
-        session.run("git", "add", "pyproject.toml", str(fragment_file), external=True)
+        session.run(
+            "git",
+            "add",
+            "src/antsibull_core/__init__.py",
+            str(fragment_file),
+            external=True,
+        )
         session.run("git", "commit", "-m", f"Prepare {version}.", external=True)
-    session.run("antsibull-changelog", "release")
+    session.run("antsibull-changelog", "release", "--version", version)
     session.run(
         "git",
         "add",
         "CHANGELOG.rst",
         "changelogs/changelog.yaml",
         "changelogs/fragments/",
-        # pyproject.toml is not committed in the last step
+        # src/antsibull_core/__init__.py is not committed in the last step
         # when the release_summary fragment is created manually
-        "pyproject.toml",
+        "src/antsibull_core/__init__.py",
         external=True,
     )
     install(session, ".")  # Smoke test
@@ -240,6 +235,6 @@ def publish(session: nox.Session):
     install(session, "hatch")
     session.run("hatch", "publish", *session.posargs)
     version = session.run("hatch", "version", silent=True).strip()
-    _repl_version(session, f"{version}.post0")
+    session.run("hatch", "version", "post")
     session.run("git", "add", "pyproject.toml", external=True)
     session.run("git", "commit", "-m", "Post-release version bump.", external=True)

pyproject.toml

@@ -8,7 +8,9 @@ build-backend = "hatchling.build"
 
 [project]
 name = "antsibull-core"
-version = "2.1.0.post0"
+dynamic = [
+    "version",
+]
 description = "Tools for building the Ansible Distribution"
 license = "GPL-3.0-or-later AND BSD-2-Clause AND MIT AND PSF-2.0"
 license-files = {globs=["LICENSES/*.txt"]}
@@ -107,6 +109,9 @@ dev = [
 
 ]
 
+[tool.hatch.version]
+path = "src/antsibull_core/__init__.py"
+
 [tool.isort]
 profile = "black"
 

src/antsibull_core/__init__.py

@@ -2,3 +2,13 @@
 # https://www.gnu.org/licenses/gpl-3.0.txt)
 # SPDX-License-Identifier: GPL-3.0-or-later
 # SPDX-FileCopyrightText: 2020, Ansible Project
+
+"""
+Shared code used by tools for building the Ansible distribution
+"""
+
+from __future__ import annotations
+
+__version__ = "2.1.0.post0"
+
+__all__ = ("__version__",)