From 4938cc9e9abf2581cb154c6a8d1ae66eb18e0d65 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=C5=81ukasz=20Langa?= <lukasz@langa.pl>
Date: Tue, 29 Oct 2019 00:34:46 +0100
Subject: [PATCH] Reset trailing comma handling
---
src/black/__init__.py | 138 ++++++++++++++----------------------------
1 file changed, 47 insertions(+), 91 deletions(-)
diff --git a/src/black/__init__.py b/src/black/__init__.py
index d251136..2250943 100644
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -1494,69 +1494,6 @@ class Line:
Leaf(token.DOT, ".") for _ in range(3)
]
- @property
- def is_collection_with_optional_trailing_comma(self) -> bool:
- """Is this line a collection literal with a trailing comma that's optional?
-
- Note that the trailing comma in a 1-tuple is not optional.
- """
- if not self.leaves or len(self.leaves) < 4:
- return False
-
- # Look for and address a trailing colon.
- if self.leaves[-1].type == token.COLON:
- closer = self.leaves[-2]
- close_index = -2
- else:
- closer = self.leaves[-1]
- close_index = -1
- if closer.type not in CLOSING_BRACKETS or self.inside_brackets:
- return False
-
- if closer.type == token.RPAR:
- # Tuples require an extra check, because if there's only
- # one element in the tuple removing the comma unmakes the
- # tuple.
- #
- # We also check for parens before looking for the trailing
- # comma because in some cases (eg assigning a dict
- # literal) the literal gets wrapped in temporary parens
- # during parsing. This case is covered by the
- # collections.py test data.
- opener = closer.opening_bracket
- for _open_index, leaf in enumerate(self.leaves):
- if leaf is opener:
- break
-
- else:
- # Couldn't find the matching opening paren, play it safe.
- return False
-
- commas = 0
- comma_depth = self.leaves[close_index - 1].bracket_depth
- for leaf in self.leaves[_open_index + 1 : close_index]:
- if leaf.bracket_depth == comma_depth and leaf.type == token.COMMA:
- commas += 1
- if commas > 1:
- # We haven't looked yet for the trailing comma because
- # we might also have caught noop parens.
- return self.leaves[close_index - 1].type == token.COMMA
-
- elif commas == 1:
- return False # it's either a one-tuple or didn't have a trailing comma
-
- if self.leaves[close_index - 1].type in CLOSING_BRACKETS:
- close_index -= 1
- closer = self.leaves[close_index]
- if closer.type == token.RPAR:
- # TODO: this is a gut feeling. Will we ever see this?
- return False
-
- if self.leaves[close_index - 1].type != token.COMMA:
- return False
-
- return True
-
@property
def is_def(self) -> bool:
"""Is this a function definition? (Also returns True for async defs.)"""
@@ -1683,40 +1620,60 @@ class Line:
def maybe_remove_trailing_comma(self, closing: Leaf) -> bool:
"""Remove trailing comma if there is one and it's safe."""
- if not (self.leaves and self.leaves[-1].type == token.COMMA):
- return False
-
- # We remove trailing commas only in the case of importing a
- # single name from a module.
if not (
self.leaves
- and self.is_import
- and len(self.leaves) > 4
and self.leaves[-1].type == token.COMMA
and closing.type in CLOSING_BRACKETS
- and self.leaves[-4].type == token.NAME
- and (
- # regular `from foo import bar,`
- self.leaves[-4].value == "import"
- # `from foo import (bar as baz,)
- or (
- len(self.leaves) > 6
- and self.leaves[-6].value == "import"
- and self.leaves[-3].value == "as"
- )
- # `from foo import bar as baz,`
- or (
- len(self.leaves) > 5
- and self.leaves[-5].value == "import"
- and self.leaves[-3].value == "as"
- )
- )
- and closing.type == token.RPAR
):
return False
- self.remove_trailing_comma()
- return True
+ if closing.type == token.RBRACE:
+ self.remove_trailing_comma()
+ return True
+
+ if closing.type == token.RSQB:
+ comma = self.leaves[-1]
+ if comma.parent and comma.parent.type == syms.listmaker:
+ self.remove_trailing_comma()
+ return True
+
+ # 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
+
+ # Otherwise, 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
+ for _opening_index, leaf in enumerate(self.leaves):
+ if leaf is opening:
+ break
+
+ else:
+ return False
+
+ for leaf in self.leaves[_opening_index + 1 :]:
+ if leaf is closing:
+ break
+
+ bracket_depth = leaf.bracket_depth
+ if bracket_depth == depth and leaf.type == token.COMMA:
+ commas += 1
+ if leaf.parent and leaf.parent.type in {
+ syms.arglist,
+ syms.typedargslist,
+ }:
+ commas += 1
+ break
+
+ if commas > 1:
+ self.remove_trailing_comma()
+ return True
+
+ return False
def append_comment(self, comment: Leaf) -> bool:
"""Add an inline or standalone comment to the line."""
@@ -2686,7 +2643,6 @@ def transform_line(
if (
not line.contains_uncollapsable_type_comments()
and not line.should_explode
- and not line.is_collection_with_optional_trailing_comma
and (
is_line_short_enough(line, line_length=mode.line_length, line_str=line_str)
or line.contains_unsplittable_type_ignore()
--
2.39.5