Repository: psf/black
File: src/black/linegen.py (Python)

Code before:


def remove_with_parens(node: Node, parent: Node) -> None:
    """Recursively hide optional parens in `with` statements."""
    if node.type == syms.atom:
        if maybe_make_parens_invisible_in_atom(
            node,
            parent=parent,
            remove_brackets_around_comma=True,
        ):
            wrap_in_parentheses(parent, node, visible=False)
        if isinstance(node.children[1], Node):
            remove_with_parens(node.children[1], node)
    elif node.type == syms.testlist_gexp:
        for child in node.children:
            if isinstance(child, Node):
                remove_with_parens(child, node)
    elif node.type == syms.asexpr_test and not any(
        leaf.type == token.COLONEQUAL for leaf in node.leaves()
    ):
        if maybe_make_parens_invisible_in_atom(
            node.children[0],
            parent=parent,
            remove_brackets_around_comma=True,
        ):
            wrap_in_parentheses(parent, node.children[0], visible=False)


def maybe_make_parens_invisible_in_atom(
    node: LN,
    parent: LN,
    remove_brackets_around_comma: bool = False,
) -> bool:
    """If it's safe, make the parens in the atom `node` invisible, recursively.
    Additionally, remove repeated, adjacent invisible parens from the atom `node`
    as they are redundant.

    Returns whether the node should itself be wrapped in invisible parentheses.
    """
    if (
        node.type != syms.atom
        or is_empty_tuple(node)
        or is_one_tuple(node)
        or (is_yield(node) and parent.type != syms.expr_stmt)
        or (
            # This condition tries to prevent removing non-optional brackets
            # around a tuple, however, can be a bit overzealous so we provide
            # and option to skip this check for `for` and `with` statements.
            not remove_brackets_around_comma
            and max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY
        )

Review comment (refactor):
`with` is slightly more complicated to achieve in one pass so I've split this into it's own function.

Basically the different variations of bracketed with statements give pretty different parse trees so we need to recursively solve this.

`with (open("test.txt")) as f: ...`: this is an `asexpr_test`
`with (open("test.txt") as f): ...`: this is an `atom` containing an `asexpr_test`
`with (open("test.txt")) as f, (open("test.txt")) as f: ...`: this is `asexpr_test`, `COMMA`, `asexpr_test`
`with (open("test.txt") as f, open("test.txt")) as f: ...`: this is an `atom` containing a `testlist_gexp` which then contains multiple `asexpr_test`s

Code after:
        check_lpar = isinstance(child, Leaf) and (
            child.value in parens_after or comma_check
        )


def remove_with_parens(node: Node, parent: Node) -> None:
    """Recursively hide optional parens in `with` statements."""
    # Removing all unnecessary parentheses in with statements in one pass is a tad
    # complex as different variations of bracketed statements result in pretty
    # different parse trees:
    #
    # with (open("file")) as f:                       # this is an asexpr_test
    #     ...
    #
    # with (open("file") as f):                       # this is an atom containing an
    #     ...                                         # asexpr_test
    #
    # with (open("file")) as f, (open("file")) as f:  # this is asexpr_test, COMMA,
    #     ...                                         # asexpr_test
    #
    # with (open("file") as f, open("file") as f):    # an atom containing a
    #     ...                                         # testlist_gexp which then
    #                                                 # contains multiple asexpr_test(s)
    if node.type == syms.atom:
        if maybe_make_parens_invisible_in_atom(
            node,
            parent=parent,
            remove_brackets_around_comma=True,
        ):
            wrap_in_parentheses(parent, node, visible=False)
        if isinstance(node.children[1], Node):
            remove_with_parens(node.children[1], node)
    elif node.type == syms.testlist_gexp:
        for child in node.children:
            if isinstance(child, Node):
                remove_with_parens(child, node)
    elif node.type == syms.asexpr_test and not any(
        leaf.type == token.COLONEQUAL for leaf in node.leaves()
    ):
        if maybe_make_parens_invisible_in_atom(
            node.children[0],
            parent=node,
            remove_brackets_around_comma=True,
        ):
            wrap_in_parentheses(node, node.children[0], visible=False)


def maybe_make_parens_invisible_in_atom(
    node: LN,
    parent: LN,
    remove_brackets_around_comma: bool = False,