Update setup methods for weco skill

Author: aliroberts

weco/cli.py

@@ -185,11 +185,30 @@ def _parse_credit_amount(value: str) -> float:
     )
 
 
+def _add_setup_source_args(parser: argparse.ArgumentParser) -> None:
+    """Add common source arguments to a setup subparser."""
+    source_group = parser.add_mutually_exclusive_group()
+    source_group.add_argument(
+        "--local", type=str, metavar="PATH", help="Use a local weco-skill directory (creates symlink for development)"
+    )
+    source_group.add_argument("--repo", type=str, metavar="URL", help="Use a different git repo URL (for forks or testing)")
+    parser.add_argument(
+        "--ref",
+        type=str,
+        metavar="REF",
+        help="Checkout a specific branch, tag, or commit hash (used with git clone, not --local)",
+    )
+
+
 def configure_setup_parser(setup_parser: argparse.ArgumentParser) -> None:
     """Configure the setup command parser and its subcommands."""
     setup_subparsers = setup_parser.add_subparsers(dest="tool", help="AI tool to set up")
-    setup_subparsers.add_parser("claude-code", help="Set up Weco skill for Claude Code")
-    setup_subparsers.add_parser("cursor", help="Set up Weco rules for Cursor")
+
+    claude_parser = setup_subparsers.add_parser("claude-code", help="Set up Weco skill for Claude Code")
+    _add_setup_source_args(claude_parser)
+
+    cursor_parser = setup_subparsers.add_parser("cursor", help="Set up Weco rules for Cursor")
+    _add_setup_source_args(cursor_parser)
 
 
 def configure_resume_parser(resume_parser: argparse.ArgumentParser) -> None:

weco/git.py

@@ -0,0 +1,121 @@
+# weco/git.py
+"""
+Git utilities for command execution and validation.
+"""
+
+import pathlib
+import shutil
+import subprocess
+
+
+class GitError(Exception):
+    """Raised when a git command fails."""
+
+    def __init__(self, message: str, stderr: str = ""):
+        super().__init__(message)
+        self.stderr = stderr
+
+
+class GitNotFoundError(Exception):
+    """Raised when git is not available on the system."""
+
+    pass
+
+
+def is_available() -> bool:
+    """Check if git is available on the system."""
+    return shutil.which("git") is not None
+
+
+def is_repo(path: pathlib.Path) -> bool:
+    """Check if a directory is a git repository."""
+    return (path / ".git").is_dir()
+
+
+def validate_ref(ref: str) -> None:
+    """
+    Validate a git ref to prevent option injection.
+
+    Raises:
+        ValueError: If ref could be interpreted as a git option.
+    """
+    if ref.startswith("-"):
+        raise ValueError(f"Invalid git ref: {ref!r} (cannot start with '-')")
+
+
+def validate_repo_url(url: str) -> None:
+    """
+    Validate a git repository URL.
+
+    Raises:
+        ValueError: If URL doesn't match expected patterns.
+    """
+    valid_prefixes = ("git@", "https://", "http://", "ssh://", "file://", "/", "./", "../")
+    if not any(url.startswith(prefix) for prefix in valid_prefixes):
+        raise ValueError(f"Invalid repository URL: {url!r}")
+
+
+def run(*args: str, cwd: pathlib.Path | None = None, error_msg: str = "Git command failed") -> subprocess.CompletedProcess:
+    """
+    Run a git command and return the result.
+
+    Args:
+        *args: Git subcommand and arguments (e.g., "clone", url, path).
+               Do NOT include "git" — it's prepended automatically.
+        cwd: Working directory for the command.
+        error_msg: Message to include in exception on failure.
+
+    Raises:
+        GitError: If the command fails or returns non-zero.
+    """
+    cmd = ["git", *args]
+    try:
+        result = subprocess.run(cmd, cwd=cwd, capture_output=True, text=True)
+    except Exception as e:
+        raise GitError(f"{error_msg}: {e}") from e
+
+    if result.returncode != 0:
+        raise GitError(error_msg, result.stderr)
+    return result
+
+
+def clone(repo_url: str, dest: pathlib.Path, ref: str | None = None) -> None:
+    """
+    Clone a git repository.
+
+    Args:
+        repo_url: The repository URL to clone.
+        dest: Destination directory.
+        ref: Optional branch, tag, or commit to checkout after cloning.
+
+    Raises:
+        GitError: If clone or checkout fails.
+    """
+    run("clone", repo_url, str(dest), error_msg="Failed to clone repository")
+    if ref:
+        run("checkout", ref, cwd=dest, error_msg=f"Failed to checkout '{ref}'")
+
+
+def pull(repo_path: pathlib.Path) -> None:
+    """
+    Pull latest changes in a git repository.
+
+    Raises:
+        GitError: If pull fails.
+    """
+    run("pull", cwd=repo_path, error_msg="Failed to pull repository")
+
+
+def fetch_and_checkout(repo_path: pathlib.Path, ref: str) -> None:
+    """
+    Fetch all remotes and checkout a specific ref.
+
+    Args:
+        repo_path: Path to the git repository.
+        ref: Branch, tag, or commit to checkout.
+
+    Raises:
+        GitError: If fetch or checkout fails.
+    """
+    run("fetch", "--all", cwd=repo_path, error_msg="Failed to fetch from repository")
+    run("checkout", ref, cwd=repo_path, error_msg=f"Failed to checkout '{ref}'")