Fix multiline strings unnecessarily wrapped in optional parentheses

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index f335ebd828402c6167719bf23d673aa99cb15ddf..298597bcb30f8aad947056fc8583327a75814d5e 100644 (file)
--- a/black.py
+++ b/black.py
@@ -626,21 +626,22 @@ LOGIC_PRIORITY = 14
 STRING_PRIORITY = 12
 COMPARATOR_PRIORITY = 10
 MATH_PRIORITIES = {
-    token.VBAR: 8,
-    token.CIRCUMFLEX: 7,
-    token.AMPER: 6,
-    token.LEFTSHIFT: 5,
-    token.RIGHTSHIFT: 5,
-    token.PLUS: 4,
-    token.MINUS: 4,
-    token.STAR: 3,
-    token.SLASH: 3,
-    token.DOUBLESLASH: 3,
-    token.PERCENT: 3,
-    token.AT: 3,
-    token.TILDE: 2,
-    token.DOUBLESTAR: 1,
+    token.VBAR: 9,
+    token.CIRCUMFLEX: 8,
+    token.AMPER: 7,
+    token.LEFTSHIFT: 6,
+    token.RIGHTSHIFT: 6,
+    token.PLUS: 5,
+    token.MINUS: 5,
+    token.STAR: 4,
+    token.SLASH: 4,
+    token.DOUBLESLASH: 4,
+    token.PERCENT: 4,
+    token.AT: 4,
+    token.TILDE: 3,
+    token.DOUBLESTAR: 2,
 }
+DOT_PRIORITY = 1
 
 
 @dataclass
@@ -1314,7 +1315,7 @@ class LineGenerator(Visitor[Line]):
         The relevant Python language `keywords` for a given statement will be
         NAME leaves within it. This methods puts those on a separate line.
 
-        `parens` holds a set of string leaf values immeditely after which
+        `parens` holds a set of string leaf values immediately after which
         invisible parens should be put.
         """
         normalize_invisible_parens(node, parens_after=parens)
@@ -1729,6 +1730,14 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
         # Don't treat them as a delimiter.
         return 0
 
+    if (
+        leaf.type == token.DOT
+        and leaf.parent
+        and leaf.parent.type not in {syms.import_from, syms.dotted_name}
+        and (previous is None or previous.type != token.NAME)
+    ):
+        return DOT_PRIORITY
+
     if (
         leaf.type in MATH_OPERATORS
         and leaf.parent
@@ -1746,31 +1755,54 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
     ):
         return STRING_PRIORITY
 
+    if leaf.type != token.NAME:
+        return 0
+
     if (
-        leaf.type == token.NAME
-        and leaf.value == "for"
+        leaf.value == "for"
         and leaf.parent
         and leaf.parent.type in {syms.comp_for, syms.old_comp_for}
     ):
         return COMPREHENSION_PRIORITY
 
     if (
-        leaf.type == token.NAME
-        and leaf.value == "if"
+        leaf.value == "if"
         and leaf.parent
         and leaf.parent.type in {syms.comp_if, syms.old_comp_if}
     ):
         return COMPREHENSION_PRIORITY
 
+    if leaf.value in {"if", "else"} and leaf.parent and leaf.parent.type == syms.test:
+        return TERNARY_PRIORITY
+
+    if leaf.value == "is":
+        return COMPARATOR_PRIORITY
+
     if (
-        leaf.type == token.NAME
-        and leaf.value in {"if", "else"}
+        leaf.value == "in"
         and leaf.parent
-        and leaf.parent.type == syms.test
+        and leaf.parent.type in {syms.comp_op, syms.comparison}
+        and not (
+            previous is not None
+            and previous.type == token.NAME
+            and previous.value == "not"
+        )
     ):
-        return TERNARY_PRIORITY
+        return COMPARATOR_PRIORITY
+
+    if (
+        leaf.value == "not"
+        and leaf.parent
+        and leaf.parent.type == syms.comp_op
+        and not (
+            previous is not None
+            and previous.type == token.NAME
+            and previous.value == "is"
+        )
+    ):
+        return COMPARATOR_PRIORITY
 
-    if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS and leaf.parent:
+    if leaf.value in LOGIC_OPERATORS and leaf.parent:
         return LOGIC_PRIORITY
 
     return 0
@@ -2105,6 +2137,10 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]:
     except ValueError:
         raise CannotSplit("No delimiters found")
 
+    if delimiter_priority == DOT_PRIORITY:
+        if bt.delimiter_count_with_priority(delimiter_priority) == 1:
+            raise CannotSplit("Splitting a single attribute from its owner looks wrong")
+
     current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
     lowest_depth = sys.maxsize
     trailing_comma_safe = True
@@ -2325,7 +2361,7 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
                 rpar = Leaf(token.RPAR, ")")
                 index = child.remove() or 0
                 node.insert_child(index, Node(syms.atom, [lpar, child, rpar]))
-            else:
+            elif not (isinstance(child, Leaf) and is_multiline_string(child)):
                 # wrap child in invisible parentheses
                 lpar = Leaf(token.LPAR, "")
                 rpar = Leaf(token.RPAR, "")
@@ -2436,6 +2472,12 @@ def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool:
     return p.type in within
 
 
+def is_multiline_string(leaf: Leaf) -> bool:
+    """Return True if `leaf` is a multiline string that actually spans many lines."""
+    value = leaf.value.lstrip("furbFURB")
+    return value[:3] in {'"""', "'''"} and "\n" in value
+
+
 def is_stub_suite(node: Node) -> bool:
     """Return True if `node` is a suite with a stub body."""
     if (