Discover whether a file is Python 3.6+ also by stars in calls

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 15a754742cc2212656d324fab4422ddad6982289..151dc8cccfe30efd38a1555e83aaaa9a90eadb48 100644 (file)
--- a/black.py
+++ b/black.py
@@ -1,5 +1,3 @@
-#!/usr/bin/env python3
-

 import asyncio
 import pickle
 from asyncio.base_events import BaseEventLoop
 import asyncio
 import pickle
 from asyncio.base_events import BaseEventLoop


@@ -43,8 +41,9 @@ from blib2to3 import pygram, pytree
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 

-__version__ = "18.4a2"
+__version__ = "18.4a6"

 DEFAULT_LINE_LENGTH = 88
 DEFAULT_LINE_LENGTH = 88

+

 # types
 syms = pygram.python_symbols
 FileContent = str
 # types
 syms = pygram.python_symbols
 FileContent = str


@@ -88,11 +87,11 @@ class FormatError(Exception):
         self.consumed = consumed
 
     def trim_prefix(self, leaf: Leaf) -> None:
         self.consumed = consumed
 
     def trim_prefix(self, leaf: Leaf) -> None:

-        leaf.prefix = leaf.prefix[self.consumed:]
+        leaf.prefix = leaf.prefix[self.consumed :]

 
     def leaf_from_consumed(self, leaf: Leaf) -> Leaf:
         """Returns a new Leaf from the consumed part of the prefix."""
 
     def leaf_from_consumed(self, leaf: Leaf) -> Leaf:
         """Returns a new Leaf from the consumed part of the prefix."""

-        unformatted_prefix = leaf.prefix[:self.consumed]
+        unformatted_prefix = leaf.prefix[: self.consumed]

         return Leaf(token.NEWLINE, unformatted_prefix)
 
 
         return Leaf(token.NEWLINE, unformatted_prefix)
 
 


@@ -193,6 +192,7 @@ def main(
         write_back = WriteBack.YES
     report = Report(check=check, quiet=quiet)
     if len(sources) == 0:
         write_back = WriteBack.YES
     report = Report(check=check, quiet=quiet)
     if len(sources) == 0:

+        out("No paths given. Nothing to do 😴")

         ctx.exit(0)
         return
 
         ctx.exit(0)
         return
 


@@ -233,7 +233,7 @@ def reformat_one(
         else:
             cache: Cache = {}
             if write_back != WriteBack.DIFF:
         else:
             cache: Cache = {}
             if write_back != WriteBack.DIFF:

-                cache = read_cache()
+                cache = read_cache(line_length)

                 src = src.resolve()
                 if src in cache and cache[src] == get_cache_info(src):
                     changed = Changed.CACHED
                 src = src.resolve()
                 if src in cache and cache[src] == get_cache_info(src):
                     changed = Changed.CACHED


@@ -244,8 +244,8 @@ def reformat_one(
                 )
             ):
                 changed = Changed.YES
                 )
             ):
                 changed = Changed.YES

-            if write_back != WriteBack.DIFF and changed is not Changed.NO:
-                write_cache(cache, [src])
+            if write_back == WriteBack.YES and changed is not Changed.NO:
+                write_cache(cache, [src], line_length)

         report.done(src, changed)
     except Exception as exc:
         report.failed(src, str(exc))
         report.done(src, changed)
     except Exception as exc:
         report.failed(src, str(exc))


@@ -269,7 +269,7 @@ async def schedule_formatting(
     """
     cache: Cache = {}
     if write_back != WriteBack.DIFF:
     """
     cache: Cache = {}
     if write_back != WriteBack.DIFF:

-        cache = read_cache()
+        cache = read_cache(line_length)

         sources, cached = filter_cached(cache, sources)
         for src in cached:
             report.done(src, Changed.CACHED)
         sources, cached = filter_cached(cache, sources)
         for src in cached:
             report.done(src, Changed.CACHED)


@@ -311,8 +311,8 @@ async def schedule_formatting(
 
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
 
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)

-    if write_back != WriteBack.DIFF and formatted:
-        write_cache(cache, formatted)
+    if write_back == WriteBack.YES and formatted:
+        write_cache(cache, formatted, line_length)

 
 
 def format_file_in_place(
 
 
 def format_file_in_place(


@@ -581,8 +581,26 @@ UNPACKING_PARENTS = {
     syms.listmaker,
     syms.testlist_gexp,
 }
     syms.listmaker,
     syms.testlist_gexp,
 }

+TEST_DESCENDANTS = {
+    syms.test,
+    syms.lambdef,
+    syms.or_test,
+    syms.and_test,
+    syms.not_test,
+    syms.comparison,
+    syms.star_expr,
+    syms.expr,
+    syms.xor_expr,
+    syms.and_expr,
+    syms.shift_expr,
+    syms.arith_expr,
+    syms.trailer,
+    syms.term,
+    syms.power,
+}

 COMPREHENSION_PRIORITY = 20
 COMMA_PRIORITY = 10
 COMPREHENSION_PRIORITY = 20
 COMMA_PRIORITY = 10

+TERNARY_PRIORITY = 7

 LOGIC_PRIORITY = 5
 STRING_PRIORITY = 4
 COMPARATOR_PRIORITY = 3
 LOGIC_PRIORITY = 5
 STRING_PRIORITY = 4
 COMPARATOR_PRIORITY = 3


@@ -696,6 +714,10 @@ class BracketTracker:
 
         return False
 
 
         return False
 

+    def get_open_lsqb(self) -> Optional[Leaf]:
+        """Return the most recent opening square bracket (if any)."""
+        return self.bracket_match.get((self.depth - 1, token.RSQB))
+

 
 @dataclass
 class Line:
 
 @dataclass
 class Line:


@@ -721,14 +743,17 @@ class Line:
         if not has_value:
             return
 
         if not has_value:
             return
 

+        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.
         if self.leaves and not preformatted:
             # Note: at this point leaf.prefix should be empty except for
             # imports, for which we only preserve newlines.

-            leaf.prefix += whitespace(leaf)
+            leaf.prefix += whitespace(
+                leaf, complex_subscript=self.is_complex_subscript(leaf)
+            )

         if self.inside_brackets or not preformatted:
             self.bracket_tracker.mark(leaf)
             self.maybe_remove_trailing_comma(leaf)
         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)
 
         if not self.append_comment(leaf):
             self.leaves.append(leaf)
 


@@ -816,6 +841,22 @@ class Line:
             and self.leaves[0].value == "yield"
         )
 
             and self.leaves[0].value == "yield"
         )
 

+    @property
+    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
+            and self.is_class
+            and self.leaves[2].type == token.LPAR
+            and self.leaves[2].value == "("
+            and self.leaves[3].type == token.RPAR
+            and self.leaves[3].value == ")"
+        )
+

     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:
     def contains_standalone_comments(self, depth_limit: int = sys.maxsize) -> bool:
         """If so, needs to be split before emitting."""
         for leaf in self.leaves:


@@ -844,9 +885,14 @@ class Line:
                 self.remove_trailing_comma()
                 return True
 
                 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
         depth = closing.bracket_depth + 1
         commas = 0
         opening = closing.opening_bracket


@@ -857,7 +903,7 @@ class Line:
         else:
             return False
 
         else:
             return False
 

-        for leaf in self.leaves[_opening_index + 1:]:
+        for leaf in self.leaves[_opening_index + 1 :]:

             if leaf is closing:
                 break
 
             if leaf is closing:
                 break
 


@@ -918,6 +964,24 @@ class Line:
                 self.comments[i] = (comma_index - 1, comment)
         self.leaves.pop()
 
                 self.comments[i] = (comma_index - 1, comment)
         self.leaves.pop()
 

+    def is_complex_subscript(self, leaf: Leaf) -> bool:
+        """Return True iff `leaf` is part of a slice with non-trivial exprs."""
+        open_lsqb = (
+            leaf if leaf.type == token.LSQB else self.bracket_tracker.get_open_lsqb()
+        )
+        if open_lsqb is None:
+            return False
+
+        subscript_start = open_lsqb.next_sibling
+        if (
+            isinstance(subscript_start, Node)
+            and subscript_start.type == syms.subscriptlist
+        ):
+            subscript_start = child_towards(subscript_start, leaf)
+        return subscript_start is not None and any(
+            n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()
+        )
+

     def __str__(self) -> str:
         """Render the line."""
         if not self:
     def __str__(self) -> str:
         """Render the line."""
         if not self:


@@ -1040,8 +1104,14 @@ class EmptyLineTracker:
                 # Don't insert empty lines before the first line in the file.
                 return 0, 0
 
                 # Don't insert empty lines before the first line in the file.
                 return 0, 0
 

-            if self.previous_line and self.previous_line.is_decorator:
-                # Don't insert empty lines between decorators.
+            if self.previous_line.is_decorator:
+                return 0, 0
+
+            if (
+                self.previous_line.is_comment
+                and self.previous_line.depth == current_line.depth
+                and before == 0
+            ):

                 return 0, 0
 
             newlines = 2
                 return 0, 0
 
             newlines = 2


@@ -1049,9 +1119,6 @@ class EmptyLineTracker:
                 newlines -= 1
             return newlines, 0
 
                 newlines -= 1
             return newlines, 0
 

-        if current_line.is_flow_control:
-            return before, 1
-

         if (
             self.previous_line
             and self.previous_line.is_import
         if (
             self.previous_line
             and self.previous_line.is_import


@@ -1060,13 +1127,6 @@ class EmptyLineTracker:
         ):
             return (before or 1), 0
 
         ):
             return (before or 1), 0
 

-        if (
-            self.previous_line
-            and self.previous_line.is_yield
-            and (not current_line.is_yield or depth != self.previous_line.depth)
-        ):
-            return (before or 1), 0
-

         return before, 0
 
 
         return before, 0
 
 


@@ -1305,8 +1365,12 @@ BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
 ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
 
 
 ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
 
 

-def whitespace(leaf: Leaf) -> str:  # noqa C901
-    """Return whitespace prefix if needed for the given `leaf`."""
+def whitespace(leaf: Leaf, *, complex_subscript: bool) -> str:  # noqa C901
+    """Return whitespace prefix if needed for the given `leaf`.
+
+    `complex_subscript` signals whether the given leaf is part of a subscription
+    which has non-trivial arguments, like arithmetic expressions or function calls.
+    """

     NO = ""
     SPACE = " "
     DOUBLESPACE = "  "
     NO = ""
     SPACE = " "
     DOUBLESPACE = "  "


@@ -1320,7 +1384,10 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"

-    if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:
+    if (
+        t == token.COLON
+        and p.type not in {syms.subscript, syms.subscriptlist, syms.sliceop}
+    ):

         return NO
 
     prev = leaf.prev_sibling
         return NO
 
     prev = leaf.prev_sibling


@@ -1330,7 +1397,13 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
             return NO
 
         if t == token.COLON:
             return NO
 
         if t == token.COLON:

-            return SPACE if prevp.type == token.COMMA else NO
+            if prevp.type == token.COLON:
+                return NO
+
+            elif prevp.type != token.COMMA and not complex_subscript:
+                return NO
+
+            return SPACE

 
         if prevp.type == token.EQUAL:
             if prevp.parent:
 
         if prevp.type == token.EQUAL:
             if prevp.parent:


@@ -1351,7 +1424,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
         elif prevp.type == token.COLON:
             if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
 
         elif prevp.type == token.COLON:
             if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:

-                return NO
+                return SPACE if complex_subscript else NO

 
         elif (
             prevp.parent
 
         elif (
             prevp.parent


@@ -1457,7 +1530,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         if prev and prev.type == token.LPAR:
             return NO
 
         if prev and prev.type == token.LPAR:
             return NO
 

-    elif p.type == syms.subscript:
+    elif p.type in {syms.subscript, syms.sliceop}:

         # indexing
         if not prev:
             assert p.parent is not None, "subscripts are always parented"
         # indexing
         if not prev:
             assert p.parent is not None, "subscripts are always parented"


@@ -1466,7 +1539,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
             return NO
 
 
             return NO
 

-        else:
+        elif not complex_subscript:

             return NO
 
     elif p.type == syms.atom:
             return NO
 
     elif p.type == syms.atom:


@@ -1536,6 +1609,14 @@ def preceding_leaf(node: Optional[LN]) -> Optional[Leaf]:
     return None
 
 
     return None
 
 

+def child_towards(ancestor: Node, descendant: LN) -> Optional[LN]:
+    """Return the child of `ancestor` that contains `descendant`."""
+    node: Optional[LN] = descendant
+    while node and node.parent != ancestor:
+        node = node.parent
+    return node
+
+

 def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
     """Return the priority of the `leaf` delimiter, given a line break after it.
 
 def is_split_after_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
     """Return the priority of the `leaf` delimiter, given a line break after it.
 


@@ -1596,6 +1677,14 @@ def is_split_before_delimiter(leaf: Leaf, previous: Leaf = None) -> int:
     ):
         return COMPREHENSION_PRIORITY
 
     ):
         return COMPREHENSION_PRIORITY
 

+    if (
+        leaf.type == token.NAME
+        and leaf.value in {"if", "else"}
+        and leaf.parent
+        and leaf.parent.type == syms.test
+    ):
+        return TERNARY_PRIORITY
+

     if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS and leaf.parent:
         return LOGIC_PRIORITY
 
     if leaf.type == token.NAME and leaf.value in LOGIC_OPERATORS and leaf.parent:
         return LOGIC_PRIORITY
 


@@ -1707,6 +1796,8 @@ def split_line(
     split_funcs: List[SplitFunc]
     if line.is_def:
         split_funcs = [left_hand_split]
     split_funcs: List[SplitFunc]
     if line.is_def:
         split_funcs = [left_hand_split]

+    elif line.is_import:
+        split_funcs = [explode_split]

     elif line.inside_brackets:
         split_funcs = [delimiter_split, standalone_comment_split, right_hand_split]
     else:
     elif line.inside_brackets:
         split_funcs = [delimiter_split, standalone_comment_split, right_hand_split]
     else:


@@ -1739,7 +1830,8 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
     """Split line into many lines, starting with the first matching bracket pair.
 
     Note: this usually looks weird, only use this for function definitions.
     """Split line into many lines, starting with the first matching bracket pair.
 
     Note: this usually looks weird, only use this for function definitions.

-    Prefer RHS otherwise.
+    Prefer RHS otherwise.  This is why this function is not symmetrical with
+    :func:`right_hand_split` which also handles optional parentheses.

     """
     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)
     """
     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)


@@ -1779,7 +1871,10 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
 def right_hand_split(
     line: Line, py36: bool = False, omit: Collection[LeafID] = ()
 ) -> Iterator[Line]:
 def right_hand_split(
     line: Line, py36: bool = False, omit: Collection[LeafID] = ()
 ) -> Iterator[Line]:

-    """Split line into many lines, starting with the last matching bracket pair."""
+    """Split line into many lines, starting with the last matching bracket pair.
+
+    If the split was by optional parentheses, attempt splitting without them, too.
+    """

     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)
     tail = Line(depth=line.depth)
     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)
     tail = Line(depth=line.depth)


@@ -1818,20 +1913,25 @@ def right_hand_split(
     bracket_split_succeeded_or_raise(head, body, tail)
     assert opening_bracket and closing_bracket
     if (
     bracket_split_succeeded_or_raise(head, body, tail)
     assert opening_bracket and closing_bracket
     if (

+        # the opening bracket is an optional paren

         opening_bracket.type == token.LPAR
         and not opening_bracket.value
         opening_bracket.type == token.LPAR
         and not opening_bracket.value

+        # the closing bracket is an optional paren

         and closing_bracket.type == token.RPAR
         and not closing_bracket.value
         and closing_bracket.type == token.RPAR
         and not closing_bracket.value

+        # there are no delimiters or standalone comments in the body
+        and not body.bracket_tracker.delimiters
+        and not line.contains_standalone_comments(0)
+        # and it's not an import (optional parens are the only thing we can split
+        # on in this case; attempting a split without them is a waste of time)
+        and not line.is_import

     ):
     ):

-        # These parens were optional. If there aren't any delimiters or standalone
-        # comments in the body, they were unnecessary and another split without
-        # them should be attempted.
-        if not (
-            body.bracket_tracker.delimiters or line.contains_standalone_comments(0)
-        ):
-            omit = {id(closing_bracket), *omit}
+        omit = {id(closing_bracket), *omit}
+        try:

             yield from right_hand_split(line, py36=py36, omit=omit)
             return
             yield from right_hand_split(line, py36=py36, omit=omit)
             return

+        except CannotSplit:
+            pass

 
     ensure_visible(opening_bracket)
     ensure_visible(closing_bracket)
 
     ensure_visible(opening_bracket)
     ensure_visible(closing_bracket)


@@ -1973,6 +2073,26 @@ def standalone_comment_split(line: Line, py36: bool = False) -> Iterator[Line]:
         yield current_line
 
 
         yield current_line
 
 

+def explode_split(
+    line: Line, py36: bool = False, omit: Collection[LeafID] = ()
+) -> Iterator[Line]:
+    """Split by rightmost bracket and immediately split contents by a delimiter."""
+    new_lines = list(right_hand_split(line, py36, omit))
+    if len(new_lines) != 3:
+        yield from new_lines
+        return
+
+    yield new_lines[0]
+
+    try:
+        yield from delimiter_split(new_lines[1], py36)
+
+    except CannotSplit:
+        yield new_lines[1]
+
+    yield new_lines[2]
+
+

 def is_import(leaf: Leaf) -> bool:
     """Return True if the given leaf starts an import statement."""
     p = leaf.parent
 def is_import(leaf: Leaf) -> bool:
     """Return True if the given leaf starts an import statement."""
     p = leaf.parent


@@ -2034,7 +2154,7 @@ def normalize_string_quotes(leaf: Leaf) -> None:
     unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
     escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}")
     escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}")
     unescaped_new_quote = re.compile(rf"(([^\\]|^)(\\\\)*){new_quote}")
     escaped_new_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{new_quote}")
     escaped_orig_quote = re.compile(rf"([^\\]|^)\\(\\\\)*{orig_quote}")

-    body = leaf.value[first_quote_pos + len(orig_quote):-len(orig_quote)]
+    body = leaf.value[first_quote_pos + len(orig_quote) : -len(orig_quote)]

     if "r" in prefix.casefold():
         if unescaped_new_quote.search(body):
             # There's at least one unescaped new_quote in this raw string
     if "r" in prefix.casefold():
         if unescaped_new_quote.search(body):
             # There's at least one unescaped new_quote in this raw string


@@ -2076,17 +2196,7 @@ 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:
     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, "(")
             elif is_one_tuple(child):
                 # wrap child in visible parentheses
                 lpar = Leaf(token.LPAR, "(")


@@ -2103,6 +2213,29 @@ def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
         check_lpar = isinstance(child, Leaf) and child.value in parens_after
 
 
         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 (
 def is_empty_tuple(node: LN) -> bool:
     """Return True if `node` holds an empty tuple."""
     return (


@@ -2204,7 +2337,7 @@ def is_python36(node: Node) -> bool:
 
     Currently looking for:
     - f-strings; and
 
     Currently looking for:
     - f-strings; and

-    - trailing commas after * or ** in function signatures.
+    - trailing commas after * or ** in function signatures and calls.

     """
     for n in node.pre_order():
         if n.type == token.STRING:
     """
     for n in node.pre_order():
         if n.type == token.STRING:


@@ -2213,7 +2346,7 @@ def is_python36(node: Node) -> bool:
                 return True
 
         elif (
                 return True
 
         elif (

-            n.type == syms.typedargslist
+            n.type in {syms.typedargslist, syms.arglist}

             and n.children
             and n.children[-1].type == token.COMMA
         ):
             and n.children
             and n.children[-1].type == token.COMMA
         ):


@@ -2221,6 +2354,11 @@ def is_python36(node: Node) -> bool:
                 if ch.type in STARS:
                     return True
 
                 if ch.type in STARS:
                     return True
 

+                if ch.type == syms.argument:
+                    for argch in ch.children:
+                        if argch.type in STARS:
+                            return True
+

     return False
 
 
     return False
 
 


@@ -2467,18 +2605,22 @@ def sub_twice(regex: Pattern[str], replacement: str, original: str) -> str:
 
 
 CACHE_DIR = Path(user_cache_dir("black", version=__version__))
 
 
 CACHE_DIR = Path(user_cache_dir("black", version=__version__))

-CACHE_FILE = CACHE_DIR / "cache.pickle"

 
 
 
 

-def read_cache() -> Cache:
+def get_cache_file(line_length: int) -> Path:
+    return CACHE_DIR / f"cache.{line_length}.pickle"
+
+
+def read_cache(line_length: int) -> Cache:

     """Read the cache if it exists and is well formed.
 
     If it is not well formed, the call to write_cache later should resolve the issue.
     """
     """Read the cache if it exists and is well formed.
 
     If it is not well formed, the call to write_cache later should resolve the issue.
     """

-    if not CACHE_FILE.exists():
+    cache_file = get_cache_file(line_length)
+    if not cache_file.exists():

         return {}
 
         return {}
 

-    with CACHE_FILE.open("rb") as fobj:
+    with cache_file.open("rb") as fobj:

         try:
             cache: Cache = pickle.load(fobj)
         except pickle.UnpicklingError:
         try:
             cache: Cache = pickle.load(fobj)
         except pickle.UnpicklingError:


@@ -2511,13 +2653,14 @@ def filter_cached(
     return todo, done
 
 
     return todo, done
 
 

-def write_cache(cache: Cache, sources: List[Path]) -> None:
+def write_cache(cache: Cache, sources: List[Path], line_length: int) -> None:

     """Update the cache file."""
     """Update the cache file."""

+    cache_file = get_cache_file(line_length)

     try:
         if not CACHE_DIR.exists():
             CACHE_DIR.mkdir(parents=True)
         new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}}
     try:
         if not CACHE_DIR.exists():
             CACHE_DIR.mkdir(parents=True)
         new_cache = {**cache, **{src.resolve(): get_cache_info(src) for src in sources}}

-        with CACHE_FILE.open("wb") as fobj:
+        with cache_file.open("wb") as fobj:

             pickle.dump(new_cache, fobj, protocol=pickle.HIGHEST_PROTOCOL)
     except OSError:
         pass
             pickle.dump(new_cache, fobj, protocol=pickle.HIGHEST_PROTOCOL)
     except OSError:
         pass