Function _maybe_wrap_cms_in_parens

src/black/linegen.py:1686–1725

When enabled and safe, wrap the multiple context managers in invisible parens. It is only safe when `features` contain Feature.PARENTHESIZED_CONTEXT_MANAGERS.

(
    node: Node, mode: Mode, features: Collection[Feature]
)

def _maybe_wrap_cms_in_parens(
    node: Node, mode: Mode, features: Collection[Feature]
) -> None:
    """When enabled and safe, wrap the multiple context managers in invisible parens.

    It is only safe when `features` contain Feature.PARENTHESIZED_CONTEXT_MANAGERS.
    """
    if (
        Feature.PARENTHESIZED_CONTEXT_MANAGERS not in features
        or len(node.children) <= 2
        # If it's an atom, it's already wrapped in parens.
        or node.children[1].type == syms.atom
    ):
        return
    colon_index: int | None = None
    for i in range(2, len(node.children)):
        if node.children[i].type == token.COLON:
            colon_index = i
            break
    if colon_index is not None:
        lpar = Leaf(token.LPAR, "")
        rpar = Leaf(token.RPAR, "")
        context_managers = node.children[1:colon_index]
        for child in context_managers:
            child.remove()
        # After wrapping, the with_stmt will look like this:
        #   with_stmt
        #     NAME 'with'
        #     atom
        #       LPAR ''
        #       testlist_gexp
        #         ... <-- context_managers
        #       /testlist_gexp
        #       RPAR ''
        #     /atom
        #     COLON ':'
        new_child = Node(
            syms.atom, [lpar, Node(syms.testlist_gexp, context_managers), rpar]
        )
        node.insert_child(1, new_child)


def remove_with_parens(