Apply PEP604 annotation style to repository

apply_pep604.py

import re
import ast
import pathlib
from typing import Union, List


class TypeHintTransformer(ast.NodeTransformer):
    def visit_Subscript(self, node: ast.Subscript) -> ast.Subscript:
        # Only transform Union type hints in actual code (not in strings/comments)
        if (isinstance(node.value, ast.Name) and 
            node.value.id == 'Union' and 
            not isinstance(node.parent, (ast.Str, ast.Constant))):
            if isinstance(node.slice, ast.Tuple):
                # Convert Union[X, Y] to X | Y
                first = node.slice.elts[0]
                result = first
                for typ in node.slice.elts[1:]:
                    result = ast.BinOp(left=result, op=ast.BitOr(), right=typ)
                return result
        # Don't modify other subscripts
        return self.generic_visit(node)


def convert_file(file_path: pathlib.Path) -> None:
    """Convert type hints in a single file to PEP 604 format."""
    with open(file_path) as f:
        lines = f.readlines()
    
    union_pattern = re.compile(r'Union\[(.*?)\]')
    
    def replace_union(match):
        types = match.group(1).split(', ')
        return ' | '.join(types)
    
    modified = False
    new_lines = []
    
    for line in lines:
        if 'Union[' in line:
            new_line = union_pattern.sub(replace_union, line)
            if new_line != line:
                modified = True
            new_lines.append(new_line)
        else:
            new_lines.append(line)
    
    if modified:
        with open(file_path, 'w') as f:
            f.writelines(new_lines)
        print(f"Converted Union types in {file_path}")


def convert_repository(repo_path: Union[str, pathlib.Path]) -> None:
    """Convert all Python files in a repository to use PEP 604 type hints."""
    repo_path = pathlib.Path(repo_path)
    python_files = repo_path.rglob("*.py")
    
    for file_path in python_files:
        convert_file(file_path)


if __name__ == "__main__":
    import sys
    if len(sys.argv) != 2:
        print("Usage: python script.py <repository_path>")
        sys.exit(1)
        
    repo_path = sys.argv[1]
    convert_repository(repo_path)