Function _rewrite_file

libs/cli/langchain_cli/namespaces/migrate/main.py:164–195

(
    filename: str,
    codemods: List[Type[ContextAwareTransformer]],
    diff: bool,
    context: CodemodContext,
)

def _rewrite_file(
    filename: str,
    codemods: List[Type[ContextAwareTransformer]],
    diff: bool,
    context: CodemodContext,
) -> Tuple[Union[str, None], Union[List[str], None]]:
    file_path = Path(filename)
    with file_path.open("r+", encoding="utf-8") as fp:
        code = fp.read()
        fp.seek(0)

        input_tree = cst.parse_module(code)

        for codemod in codemods:
            transformer = codemod(context=context)
            output_tree = transformer.transform_module(input_tree)
            input_tree = output_tree

        output_code = input_tree.code
        if code != output_code:
            if diff:
                lines = difflib.unified_diff(
                    code.splitlines(keepends=True),
                    output_code.splitlines(keepends=True),
                    fromfile=filename,
                    tofile=filename,
                )
                return None, list(lines)
            else:
                fp.write(output_code)
                fp.truncate()
    return None, None


def _rewrite_notebook(