githelpers.py

#!/usr/bin/env python
# Copyright 2023 UT-Battelle, LLC, and other Celeritas developers.
# See the top-level COPYRIGHT file for details.
# SPDX-License-Identifier: (Apache-2.0 OR MIT)
"""
Helper functions for release note generation and other GitHub processing.
"""

import re
import subprocess

from pathlib import Path
from contextlib import contextmanager


MISSING_PR_ID = {
    "Fix linking to CUDA toolkit when using VecGeom": 989,
}
GIT = "git"
CELERITAS_REPO = Path.home() / "Code/celeritas"
RE_SUBJECT_PR_SQUASH = re.compile(r"\(#([\d]+)\)$")
RE_SUBJECT_PR_MERGE = re.compile(r"^Merge pull request #([\d]+)")


def git(*args, split=b"\n"):
    result = subprocess.run(
        (GIT,) + args,
        capture_output=True,
        check=True,
        env={"GIT_DIR": str(CELERITAS_REPO / ".git")},
    )
    return [s.decode() for s in result.stdout.split(split)]


def gitz(subcommand, *args):
    return git(subcommand, "-z", *args, split=b"\0")


def git_log_subjects(start, stop, first_parent=True):
    span = stop
    if start:
        span = start + ".." + stop
    args = []
    if first_parent:
        args.append("--first-parent")
    args += [r"--format=%s", span]
    return git("log", *args)


def git_merge_base(a, b):
    return git("merge-base", a, b)[0]


def subject_to_pr(subj):
    for expr in [RE_SUBJECT_PR_SQUASH, RE_SUBJECT_PR_MERGE]:
        if match := expr.search(subj):
            return int(match.group(1))
    if subj:
        try:
            return MISSING_PR_ID[subj]
        except KeyError:
            print("Can't match log subject to PR:", subj)


def git_renames(old_ref: str, new_ref: str):
    names = iter(gitz("diff", "--name-status", old_ref, new_ref))
    try:
        while True:
            delta = next(names)
            if delta.startswith("R"):
                yield (next(names), next(names))
            else:
                skipped = next(names)
                print(f"WARNING: not a rename: {delta}, {skipped}")
    except StopIteration:
        pass


def git_lstree(ref: str):
    return gitz("ls-tree", "-r", "--name-only", ref)

@contextmanager
def open_pbcopy():
    """Write to the clipboard as though to a text file.
    """
    process = subprocess.Popen(
        ["pbcopy"], 
        stdin=subprocess.PIPE, 
        env={"LANG": "en_US.UTF-8"},
        encoding="utf-8",
    )
    try:
        writer = process.stdin
        yield writer
    finally:
        writer.close()
        process.wait()