chore: add release script

Author: leodevian

pyproject.toml

@@ -63,7 +63,9 @@ lint = [
   "pre-commit-uv>=4.1.4",
 ]
 release = [
+  "packaging>=24.2",
   "towncrier>=24.8",
+  "uv>=0.7.7",
 ]
 
 [tool.ruff]

scripts/release.py

@@ -0,0 +1,162 @@
+# /// script
+# requires-python = ">=3.10"
+# dependencies = [
+#   "packaging>=24.2",
+#   "towncrier>=24.8",
+#   "uv>=0.7.7",
+# ]
+# ///
+"""Automation for releases."""
+
+# ruff: noqa: T201
+
+from __future__ import annotations
+
+import argparse
+import subprocess
+import sys
+from functools import partial
+from typing import TYPE_CHECKING
+
+from packaging.version import Version
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+print_error = partial(print, file=sys.stderr)
+
+run = partial(
+    subprocess.check_call,
+    stdout=subprocess.DEVNULL,
+    stderr=subprocess.DEVNULL,
+)
+
+
+def main(argv: Sequence[str] | None = None) -> int:  # noqa: PLR0911, PLR0915
+    """Prepare a new release."""
+    # Parse command-line arguments.
+    parser = argparse.ArgumentParser(description="prepare a new release")
+    parser.add_argument(
+        "--version",
+        type=Version,
+        required=True,
+        help="provide the release version",
+    )
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="perform a dry run",
+    )
+    args = parser.parse_args(argv)
+
+    # Get the public portion of the version.
+    version = args.version.public
+
+    # Check if the Git repository is dirty.
+    try:
+        run(("git", "diff", "--quiet"))
+
+    except subprocess.CalledProcessError:
+        print_error("The Git repository is dirty.")
+        return 1
+
+    # Get the name of the base branch.
+    base_branch = subprocess.check_output(
+        ("git", "rev-parse", "--abbrev-ref", "HEAD"),
+        encoding="utf-8",
+    ).rstrip()
+
+    # Create the release branch.
+    release_branch = f"release/{version}"
+
+    try:
+        run(("git", "branch", release_branch))
+
+    except subprocess.CalledProcessError:
+        print_error(f"The release branch already exists: {release_branch!r}.")
+        return 1
+
+    print(f"Created release branch {release_branch!r}.")
+
+    # Switch to the release branch.
+    run(("git", "checkout", release_branch))
+
+    print(f"Switched from branch {base_branch!r} to release branch {release_branch!r}.")
+
+    # Bump the version.
+    try:
+        run(("uv", "version", "--no-sync", version))
+        run(("towncrier", "build", "--yes", "--version", version))
+
+    except subprocess.CalledProcessError:
+        run(("git", "checkout", base_branch))
+        run(("git", "branch", "-D", release_branch))
+        print_error("An error occurred while bumping the version.")
+        print_error(
+            f"Removed release branch {release_branch!r} "
+            f"and switched back to {base_branch!r}."
+        )
+        return 1
+
+    # Commit changes.
+    run(("git", "add", ":/pyproject.toml", ":/uv.lock"))
+    run(("git", "add", "-A", ":/changelog.d/*", ":/CHANGELOG.md"))
+    run(("git", "commit", "-m", f"chore: prepare release {version}", "--no-verify"))
+
+    print(f"Committed changes on branch {release_branch!r}.")
+
+    # Create the release tag.
+    release_tag = f"v{version}"
+
+    try:
+        run(("git", "tag", "-a", release_tag, "-m", f"bump version to {version}"))
+
+    except subprocess.CalledProcessError:
+        run(("git", "checkout", base_branch))
+        run(("git", "branch", "-D", release_branch))
+        print_error(f"The release tag already exists: {release_tag!r}.")
+        print_error(
+            f"Removed release branch {release_branch!r} "
+            f"and switched back to {base_branch!r}."
+        )
+        return 1
+
+    # Exit on dry run.
+    if args.dry_run:
+        print("Dry run success!")
+        run(("git", "checkout", base_branch))
+        run(("git", "branch", "-D", release_branch))
+        print(
+            f"Removed release branch {release_branch!r} "
+            f"and switched back to {base_branch!r}."
+        )
+        run(("git", "tag", "-d", release_tag))
+        print(f"Removed release tag {release_tag!r}.")
+        return 0
+
+    # Push changes to the remote repository and push the release tag.
+    try:
+        run(("git", "push", "origin", f"{release_branch}:main", "--follow-tags"))
+
+    except subprocess.CalledProcessError:
+        run(("git", "checkout", base_branch))
+        run(("git", "branch", "-D", release_branch))
+        print_error("An error occurred while pushing changes.")
+        print_error(
+            f"Removed release branch {release_branch!r} "
+            f"and switched back to {base_branch!r}."
+        )
+        return 1
+
+    print(f"Pushed changes from {release_branch!r} to 'origin/main'.")
+
+    # Remove the release branch and switch to the main branch.
+    run(("git", "checkout", "main"))
+    run(("git", "branch", "-D", release_branch))
+    run(("git", "fetch"))
+    run(("git", "reset", "--hard", "origin/main"))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

tox.toml

@@ -66,3 +66,15 @@ commands = [
     { replace = "posargs", extend = true },
   ],
 ]
+
+[env.release]
+description = "prepare a new release"
+skip_install = true
+dependency_groups = [ "release" ]
+commands = [
+  [
+    "python",
+    "{tox_root}{/}scripts{/}release.py",
+    { replace = "posargs", extend = true },
+  ],
+]