Class SnapshotStore

unity_cli/api/uitree_snapshot.py:33–87

Save and compare UI tree snapshots.

class SnapshotStore:
    """Save and compare UI tree snapshots."""

    def __init__(self, snapshot_dir: Path = SNAPSHOT_DIR) -> None:
        self._dir = snapshot_dir

    def _path(self, name: str) -> Path:
        if not SNAPSHOT_NAME_RE.fullmatch(name):
            msg = f"Invalid snapshot name: {name!r}"
            raise ValueError(msg)
        return self._dir / f"{name}.json"

    def save(self, name: str, data: dict[str, Any]) -> Path:
        """Save a tree dump as a named snapshot."""
        self._dir.mkdir(parents=True, exist_ok=True)
        path = self._path(name)
        path.write_text(json.dumps(data, ensure_ascii=False), encoding="utf-8")
        return path

    def load(self, name: str) -> dict[str, Any] | None:
        """Load a saved snapshot. Returns None if not found."""
        path = self._path(name)
        if not path.exists():
            return None
        try:
            result: dict[str, Any] = json.loads(path.read_text(encoding="utf-8"))
            return result
        except (json.JSONDecodeError, OSError):
            return None

    def diff(self, name: str, current: dict[str, Any]) -> dict[str, Any]:
        """Compare current tree against a saved snapshot."""
        baseline = self.load(name)
        if baseline is None:
            msg = f"Snapshot not found: {name!r}"
            raise FileNotFoundError(msg)

        baseline_elements = _collect_elements(baseline)
        current_elements = _collect_elements(current)

        return _compare_elements(baseline_elements, current_elements)

    def list_names(self) -> list[str]:
        """List all saved snapshot names."""
        if not self._dir.exists():
            return []
        return sorted(p.stem for p in self._dir.glob("*.json"))

    def delete(self, name: str) -> bool:
        """Delete a saved snapshot. Returns True if deleted."""
        path = self._path(name)
        if path.exists():
            path.unlink()
            return True
        return False


def _collect_elements(data: dict[str, Any]) -> list[dict[str, Any]]: