Strip redundant parentheses from assignment exprs (#1906)

[etc/vim.git] / src / black / __init__.py

diff --git a/src/black/__init__.py b/src/black/__init__.py
index c1907d9b1f10dd47a19d30df5686d9885fda4fdb..a1d16d9bdeb222f9d5d2a811c52f3671323cfe6e 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -883,7 +883,7 @@ def format_file_in_place(
         dst_name = f"{src}\t{now} +0000"
         diff_contents = diff(src_contents, dst_contents, src_name, dst_name)
 
-        if write_back == write_back.COLOR_DIFF:
+        if write_back == WriteBack.COLOR_DIFF:
             diff_contents = color_diff(diff_contents)
 
         with lock or nullcontext():
@@ -1480,7 +1480,7 @@ class Line:
     comments: Dict[LeafID, List[Leaf]] = field(default_factory=dict)
     bracket_tracker: BracketTracker = field(default_factory=BracketTracker)
     inside_brackets: bool = False
-    should_split: bool = False
+    should_split_rhs: bool = False
     magic_trailing_comma: Optional[Leaf] = None
 
     def append(self, leaf: Leaf, preformatted: bool = False) -> None:
@@ -1792,7 +1792,7 @@ class Line:
             mode=self.mode,
             depth=self.depth,
             inside_brackets=self.inside_brackets,
-            should_split=self.should_split,
+            should_split_rhs=self.should_split_rhs,
             magic_trailing_comma=self.magic_trailing_comma,
         )
 
@@ -2049,6 +2049,8 @@ class LineGenerator(Visitor[Line]):
 
     def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
         """Visit a statement without nested statements."""
+        if first_child_is_arith(node):
+            wrap_in_parentheses(node, node.children[0], visible=False)
         is_suite_like = node.parent and node.parent.type in STATEMENT
         if is_suite_like:
             if self.mode.is_pyi and is_stub_body(node):
@@ -2712,7 +2714,7 @@ def transform_line(
     transformers: List[Transformer]
     if (
         not line.contains_uncollapsable_type_comments()
-        and not line.should_split
+        and not line.should_split_rhs
         and not line.magic_trailing_comma
         and (
             is_line_short_enough(line, line_length=mode.line_length, line_str=line_str)
@@ -4387,7 +4389,7 @@ class StringParenWrapper(CustomSplitMapMixin, BaseStringSplitter):
             mode=line.mode,
             depth=line.depth + 1,
             inside_brackets=True,
-            should_split=line.should_split,
+            should_split_rhs=line.should_split_rhs,
             magic_trailing_comma=line.magic_trailing_comma,
         )
         string_leaf = Leaf(token.STRING, string_value)
@@ -5010,7 +5012,7 @@ def bracket_split_build_line(
         for comment_after in original.comments_after(leaf):
             result.append(comment_after, preformatted=True)
     if is_body and should_split_line(result, opening_bracket):
-        result.should_split = True
+        result.should_split_rhs = True
     return result
 
 
@@ -5368,10 +5370,7 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
             check_lpar = True
 
         if check_lpar:
-            if is_walrus_assignment(child):
-                pass
-
-            elif child.type == syms.atom:
+            if child.type == syms.atom:
                 if maybe_make_parens_invisible_in_atom(child, parent=node):
                     wrap_in_parentheses(node, child, visible=False)
             elif is_one_tuple(child):
@@ -5543,6 +5542,7 @@ def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
     Returns whether the node should itself be wrapped in invisible parentheses.
 
     """
+
     if (
         node.type != syms.atom
         or is_empty_tuple(node)
@@ -5552,6 +5552,10 @@ def maybe_make_parens_invisible_in_atom(node: LN, parent: LN) -> bool:
     ):
         return False
 
+    if is_walrus_assignment(node):
+        if parent.type in [syms.annassign, syms.expr_stmt]:
+            return False
+
     first = node.children[0]
     last = node.children[-1]
     if first.type == token.LPAR and last.type == token.RPAR:
@@ -5613,6 +5617,17 @@ def unwrap_singleton_parenthesis(node: LN) -> Optional[LN]:
     return wrapped
 
 
+def first_child_is_arith(node: Node) -> bool:
+    """Whether first child is an arithmetic or a binary arithmetic expression"""
+    expr_types = {
+        syms.arith_expr,
+        syms.shift_expr,
+        syms.xor_expr,
+        syms.and_expr,
+    }
+    return bool(node.children and node.children[0].type in expr_types)
+
+
 def wrap_in_parentheses(parent: Node, child: LN, *, visible: bool = True) -> None:
     """Wrap `child` in parentheses.