1 files changed, 81 insertions, 0 deletions
diff --git a/tools/finalize.py b/tools/finalize.py
new file mode 100644
index 00000000..98b06c07
--- /dev/null
+++ b/tools/finalize.py
@@ -0,0 +1,81 @@
+"""
+Finalize the repo for a release. Invokes towncrier and bumpversion.
+"""
+
+__requires__ = ['bump2version', 'towncrier']
+
+
+import subprocess
+import pathlib
+import re
+import sys
+
+
+def release_kind():
+    """
+    Determine which release to make based on the files in the
+    changelog.
+    """
+    # use min here as 'major' < 'minor' < 'patch'
+    return min(
+        'major' if 'breaking' in file.name else
+        'minor' if 'change' in file.name else
+        'patch'
+        for file in pathlib.Path('changelog.d').iterdir()
+    )
+
+
+bump_version_command = [
+    sys.executable,
+    '-m', 'bumpversion',
+    release_kind(),
+]
+
+
+def get_version():
+    cmd = bump_version_command + ['--dry-run', '--verbose']
+    out = subprocess.check_output(cmd, text=True)
+    return re.search('^new_version=(.*)', out, re.MULTILINE).group(1)
+
+
+def update_changelog():
+    cmd = [
+        sys.executable, '-m',
+        'towncrier',
+        '--version', get_version(),
+        '--yes',
+    ]
+    subprocess.check_call(cmd)
+
+
+def bump_version():
+    cmd = bump_version_command + ['--allow-dirty']
+    subprocess.check_call(cmd)
+
+
+def ensure_config():
+    """
+    Double-check that Git has an e-mail configured.
+    """
+    subprocess.check_output(['git', 'config', 'user.email'])
+
+
+def check_changes():
+    """
+    Verify that all of the files in changelog.d have the appropriate
+    names.
+    """
+    allowed = 'deprecation', 'breaking', 'change', 'doc', 'misc'
+    assert all(
+        any(key in file.name for key in allowed)
+        for file in pathlib.Path('changelog.d').iterdir()
+        if file.name != '.gitignore'
+    )
+
+
+if __name__ == '__main__':
+    print("Cutting release at", get_version())
+    ensure_config()
+    check_changes()
+    update_changelog()
+    bump_version()