Files
cross-eval/cross_eval/worktree.py

153 lines
4.2 KiB
Python

"""Git worktree lifecycle management for agentic mode."""
from __future__ import annotations
import logging
import shutil
import subprocess
import tempfile
from datetime import datetime
from pathlib import Path
logger = logging.getLogger(__name__)
class WorktreeError(RuntimeError):
"""Error during worktree operations."""
def make_branch_name(preset_name: str) -> str:
"""Generate a branch name for agentic results."""
ts = datetime.now().strftime("%Y%m%d_%H%M%S")
return f"cross-eval/{preset_name}_{ts}"
def make_worktree_dir(base_cwd: Path, branch_name: str) -> Path:
"""Choose a worktree directory outside the base repo.
Keeping agentic worktrees outside the source checkout avoids tools that
incorrectly walk up to the outer repo and write into the base worktree.
"""
repo_name = base_cwd.resolve().name or "repo"
branch_slug = branch_name.replace("/", "__")
return (
Path(tempfile.gettempdir())
/ "cross-eval-worktrees"
/ repo_name
/ branch_slug
)
def create_worktree(base_cwd: Path, work_dir: Path, branch_name: str) -> Path:
"""Create a git worktree on a new branch from HEAD.
1. Create branch from HEAD
2. Create worktree checked out to that branch
The branch lives in the original repo, so it survives worktree removal.
"""
work_dir = work_dir.resolve()
if work_dir.exists():
shutil.rmtree(work_dir)
# Create the branch at HEAD
try:
subprocess.run(
["git", "branch", branch_name, "HEAD"],
cwd=base_cwd,
capture_output=True,
text=True,
check=True,
)
except subprocess.CalledProcessError as e:
raise WorktreeError(
f"Failed to create branch '{branch_name}': {e.stderr.strip()}"
) from e
# Create worktree on that branch
try:
subprocess.run(
["git", "worktree", "add", str(work_dir), branch_name],
cwd=base_cwd,
capture_output=True,
text=True,
check=True,
)
except subprocess.CalledProcessError as e:
# Clean up the branch if worktree creation fails
subprocess.run(
["git", "branch", "-D", branch_name],
cwd=base_cwd,
capture_output=True,
)
raise WorktreeError(
f"Failed to create worktree at {work_dir}: {e.stderr.strip()}"
) from e
logger.debug("Created worktree on branch '%s': %s", branch_name, work_dir)
return work_dir
def capture_diff(worktree_path: Path) -> str:
"""Capture all changes made in the worktree as a unified diff.
Includes both tracked modifications and new untracked files.
"""
subprocess.run(
["git", "add", "-A"],
cwd=worktree_path,
capture_output=True,
check=True,
)
result = subprocess.run(
["git", "diff", "--cached", "HEAD"],
cwd=worktree_path,
capture_output=True,
text=True,
)
return result.stdout.strip()
def commit_worktree(worktree_path: Path, message: str) -> bool:
"""Stage and commit all changes in the worktree.
Returns True if a commit was made, False if nothing to commit.
"""
subprocess.run(
["git", "add", "-A"],
cwd=worktree_path,
capture_output=True,
check=True,
)
result = subprocess.run(
["git", "commit", "-m", message],
cwd=worktree_path,
capture_output=True,
text=True,
)
# exit code 1 = nothing to commit
return result.returncode == 0
def remove_worktree(base_cwd: Path, work_dir: Path) -> None:
"""Remove a git worktree (branch is preserved in the original repo)."""
work_dir = work_dir.resolve()
try:
subprocess.run(
["git", "worktree", "remove", "--force", str(work_dir)],
cwd=base_cwd,
capture_output=True,
text=True,
check=True,
)
except subprocess.CalledProcessError:
if work_dir.exists():
shutil.rmtree(work_dir, ignore_errors=True)
subprocess.run(
["git", "worktree", "prune"],
cwd=base_cwd,
capture_output=True,
)
logger.debug("Removed worktree: %s (branch preserved)", work_dir)