Make parentheses invisible recursively in atoms

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index cfb5028d68d85be324c450838f7797ecbe22e5fd..34bdcf900dd50b2601a610d428006a1fdc06f59f 100644 (file)
--- a/black.py
+++ b/black.py
@@ -743,9 +743,8 @@ class Line:
         if not has_value:
             return
 
-        if token.COLON == leaf.type and self.is_class_parenth_empty:
+        if token.COLON == leaf.type and self.is_class_paren_empty:
             del self.leaves[-2:]
-
         if self.leaves and not preformatted:
             # Note: at this point leaf.prefix should be empty except for
             # imports, for which we only preserve newlines.
@@ -755,7 +754,6 @@ class Line:
         if self.inside_brackets or not preformatted:
             self.bracket_tracker.mark(leaf)
             self.maybe_remove_trailing_comma(leaf)
-
         if not self.append_comment(leaf):
             self.leaves.append(leaf)
 
@@ -844,8 +842,11 @@ class Line:
         )
 
     @property
-    def is_class_parenth_empty(self) -> bool:
-        """Is this class parentheses blank?"""
+    def is_class_paren_empty(self) -> bool:
+        """Is this a class with no base classes but using parentheses?
+
+        Those are unnecessary and should be removed.
+        """
         return (
             bool(self)
             and len(self.leaves) == 4
@@ -884,9 +885,14 @@ class Line:
                 self.remove_trailing_comma()
                 return True
 
-        # For parens let's check if it's safe to remove the comma.  If the
-        # trailing one is the only one, we might mistakenly change a tuple
-        # into a different type by removing the comma.
+        # For parens let's check if it's safe to remove the comma.
+        # Imports are always safe.
+        if self.is_import:
+            self.remove_trailing_comma()
+            return True
+
+        # Otheriwsse, if the trailing one is the only one, we might mistakenly
+        # change a tuple into a different type by removing the comma.
         depth = closing.bracket_depth + 1
         commas = 0
         opening = closing.opening_bracket
@@ -1141,7 +1147,6 @@ class LineGenerator(Visitor[Line]):
 
         If any lines were generated, set up a new current_line.
         """
-
         if not self.current_line:
             if self.current_line.__class__ == type:
                 self.current_line.depth += indent
@@ -2182,17 +2187,7 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
     for child in list(node.children):
         if check_lpar:
             if child.type == syms.atom:
-                if not (
-                    is_empty_tuple(child)
-                    or is_one_tuple(child)
-                    or max_delimiter_priority_in_atom(child) >= COMMA_PRIORITY
-                ):
-                    first = child.children[0]
-                    last = child.children[-1]
-                    if first.type == token.LPAR and last.type == token.RPAR:
-                        # make parentheses invisible
-                        first.value = ""  # type: ignore
-                        last.value = ""  # type: ignore
+                maybe_make_parens_invisible_in_atom(child)
             elif is_one_tuple(child):
                 # wrap child in visible parentheses
                 lpar = Leaf(token.LPAR, "(")
@@ -2209,6 +2204,29 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
         check_lpar = isinstance(child, Leaf) and child.value in parens_after
 
 
+def maybe_make_parens_invisible_in_atom(node: LN) -> bool:
+    """If it's safe, make the parens in the atom `node` invisible, recusively."""
+    if (
+        node.type != syms.atom
+        or is_empty_tuple(node)
+        or is_one_tuple(node)
+        or max_delimiter_priority_in_atom(node) >= COMMA_PRIORITY
+    ):
+        return False
+
+    first = node.children[0]
+    last = node.children[-1]
+    if first.type == token.LPAR and last.type == token.RPAR:
+        # make parentheses invisible
+        first.value = ""  # type: ignore
+        last.value = ""  # type: ignore
+        if len(node.children) > 1:
+            maybe_make_parens_invisible_in_atom(node.children[1])
+        return True
+
+    return False
+
+
 def is_empty_tuple(node: LN) -> bool:
     """Return True if `node` holds an empty tuple."""
     return (