Improvements to contributing docs (#3753)

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

diff --git a/src/black/lines.py b/src/black/lines.py
index b65604864a4b73fabb69f893e13b99c39806ea93..ea8fe520756d3a61702cf9e81453416bf534b632 100644 (file)
--- a/src/black/lines.py
+++ b/src/black/lines.py
@@ -15,7 +15,7 @@ from typing import (
     cast,
 )
 
     cast,
 )
 

-from black.brackets import DOT_PRIORITY, BracketTracker
+from black.brackets import COMMA_PRIORITY, DOT_PRIORITY, BracketTracker

 from black.mode import Mode, Preview
 from black.nodes import (
     BRACKETS,
 from black.mode import Mode, Preview
 from black.nodes import (
     BRACKETS,


@@ -28,10 +28,13 @@ from black.nodes import (
     is_multiline_string,
     is_one_sequence_between,
     is_type_comment,
     is_multiline_string,
     is_one_sequence_between,
     is_type_comment,

+    is_type_ignore_comment,
+    is_with_or_async_with_stmt,

     replace_child,
     syms,
     whitespace,
 )
     replace_child,
     syms,
     whitespace,
 )

+from black.strings import str_width

 from blib2to3.pgen2 import token
 from blib2to3.pytree import Leaf, Node
 
 from blib2to3.pgen2 import token
 from blib2to3.pytree import Leaf, Node
 


@@ -122,6 +125,11 @@ class Line:
         """Is this an import line?"""
         return bool(self) and is_import(self.leaves[0])
 
         """Is this an import line?"""
         return bool(self) and is_import(self.leaves[0])
 

+    @property
+    def is_with_or_async_with_stmt(self) -> bool:
+        """Is this a with_stmt line?"""
+        return bool(self) and is_with_or_async_with_stmt(self.leaves[0])
+

     @property
     def is_class(self) -> bool:
         """Is this line a class definition?"""
     @property
     def is_class(self) -> bool:
         """Is this line a class definition?"""


@@ -189,6 +197,26 @@ class Line:
             return False
         return self.leaves[-1].type == token.COLON
 
             return False
         return self.leaves[-1].type == token.COLON
 

+    def is_fmt_pass_converted(
+        self, *, first_leaf_matches: Optional[Callable[[Leaf], bool]] = None
+    ) -> bool:
+        """Is this line converted from fmt off/skip code?
+
+        If first_leaf_matches is not None, it only returns True if the first
+        leaf of converted code matches.
+        """
+        if len(self.leaves) != 1:
+            return False
+        leaf = self.leaves[0]
+        if (
+            leaf.type != STANDALONE_COMMENT
+            or leaf.fmt_pass_converted_first_leaf is None
+        ):
+            return False
+        return first_leaf_matches is None or first_leaf_matches(
+            leaf.fmt_pass_converted_first_leaf
+        )
+

     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:


@@ -224,7 +252,7 @@ class Line:
             for comment in comments:
                 if is_type_comment(comment):
                     if comment_seen or (
             for comment in comments:
                 if is_type_comment(comment):
                     if comment_seen or (

-                        not is_type_comment(comment, " ignore")
+                        not is_type_ignore_comment(comment)

                         and leaf_id not in ignored_ids
                     ):
                         return True
                         and leaf_id not in ignored_ids
                     ):
                         return True


@@ -261,7 +289,7 @@ class Line:
             # line.
             for node in self.leaves[-2:]:
                 for comment in self.comments.get(id(node), []):
             # line.
             for node in self.leaves[-2:]:
                 for comment in self.comments.get(id(node), []):

-                    if is_type_comment(comment, " ignore"):
+                    if is_type_ignore_comment(comment):

                         return True
 
         return False
                         return True
 
         return False


@@ -449,6 +477,17 @@ class Line:
         return bool(self.leaves or self.comments)
 
 
         return bool(self.leaves or self.comments)
 
 

+@dataclass
+class RHSResult:
+    """Intermediate split result from a right hand split."""
+
+    head: Line
+    body: Line
+    tail: Line
+    opening_bracket: Leaf
+    closing_bracket: Leaf
+
+

 @dataclass
 class LinesBlock:
     """Class that holds information about a block of formatted lines.
 @dataclass
 class LinesBlock:
     """Class that holds information about a block of formatted lines.


@@ -484,7 +523,7 @@ class EmptyLineTracker:
     mode: Mode
     previous_line: Optional[Line] = None
     previous_block: Optional[LinesBlock] = None
     mode: Mode
     previous_line: Optional[Line] = None
     previous_block: Optional[LinesBlock] = None

-    previous_defs: List[int] = field(default_factory=list)
+    previous_defs: List[Line] = field(default_factory=list)

     semantic_leading_comment: Optional[LinesBlock] = None
 
     def maybe_empty_lines(self, current_line: Line) -> LinesBlock:
     semantic_leading_comment: Optional[LinesBlock] = None
 
     def maybe_empty_lines(self, current_line: Line) -> LinesBlock:


@@ -540,12 +579,18 @@ class EmptyLineTracker:
         else:
             before = 0
         depth = current_line.depth
         else:
             before = 0
         depth = current_line.depth

-        while self.previous_defs and self.previous_defs[-1] >= depth:
+        while self.previous_defs and self.previous_defs[-1].depth >= depth:

             if self.mode.is_pyi:
                 assert self.previous_line is not None
                 if depth and not current_line.is_def and self.previous_line.is_def:
                     # Empty lines between attributes and methods should be preserved.
                     before = min(1, before)
             if self.mode.is_pyi:
                 assert self.previous_line is not None
                 if depth and not current_line.is_def and self.previous_line.is_def:
                     # Empty lines between attributes and methods should be preserved.
                     before = min(1, before)

+                elif (
+                    Preview.blank_line_after_nested_stub_class in self.mode
+                    and self.previous_defs[-1].is_class
+                    and not self.previous_defs[-1].is_stub_class
+                ):
+                    before = 1

                 elif depth:
                     before = 0
                 else:
                 elif depth:
                     before = 0
                 else:


@@ -555,7 +600,7 @@ class EmptyLineTracker:
                     before = 1
                 elif (
                     not depth
                     before = 1
                 elif (
                     not depth

-                    and self.previous_defs[-1]
+                    and self.previous_defs[-1].depth

                     and current_line.leaves[-1].type == token.COLON
                     and (
                         current_line.leaves[0].value
                     and current_line.leaves[-1].type == token.COLON
                     and (
                         current_line.leaves[0].value


@@ -580,6 +625,7 @@ class EmptyLineTracker:
             self.previous_line
             and self.previous_line.is_import
             and not current_line.is_import
             self.previous_line
             and self.previous_line.is_import
             and not current_line.is_import

+            and not current_line.is_fmt_pass_converted(first_leaf_matches=is_import)

             and depth == self.previous_line.depth
         ):
             return (before or 1), 0
             and depth == self.previous_line.depth
         ):
             return (before or 1), 0


@@ -589,6 +635,8 @@ class EmptyLineTracker:
             and self.previous_line.is_class
             and current_line.is_triple_quoted_string
         ):
             and self.previous_line.is_class
             and current_line.is_triple_quoted_string
         ):

+            if Preview.no_blank_line_before_class_docstring in current_line.mode:
+                return 0, 1

             return before, 1
 
         if self.previous_line and self.previous_line.opens_block:
             return before, 1
 
         if self.previous_line and self.previous_line.opens_block:


@@ -599,7 +647,7 @@ class EmptyLineTracker:
         self, current_line: Line, before: int
     ) -> Tuple[int, int]:
         if not current_line.is_decorator:
         self, current_line: Line, before: int
     ) -> Tuple[int, int]:
         if not current_line.is_decorator:

-            self.previous_defs.append(current_line.depth)
+            self.previous_defs.append(current_line)

         if self.previous_line is None:
             # Don't insert empty lines before the first line in the file.
             return 0, 0
         if self.previous_line is None:
             # Don't insert empty lines before the first line in the file.
             return 0, 0


@@ -715,9 +763,11 @@ def is_line_short_enough(  # noqa: C901
     if not line_str:
         line_str = line_to_string(line)
 
     if not line_str:
         line_str = line_to_string(line)
 

+    width = str_width if mode.preview else len
+

     if Preview.multiline_string_handling not in mode:
         return (
     if Preview.multiline_string_handling not in mode:
         return (

-            len(line_str) <= mode.line_length
+            width(line_str) <= mode.line_length

             and "\n" not in line_str  # multiline strings
             and not line.contains_standalone_comments()
         )
             and "\n" not in line_str  # multiline strings
             and not line.contains_standalone_comments()
         )


@@ -726,10 +776,10 @@ def is_line_short_enough(  # noqa: C901
         return False
     if "\n" not in line_str:
         # No multiline strings (MLS) present
         return False
     if "\n" not in line_str:
         # No multiline strings (MLS) present

-        return len(line_str) <= mode.line_length
+        return width(line_str) <= mode.line_length

 
     first, *_, last = line_str.split("\n")
 
     first, *_, last = line_str.split("\n")

-    if len(first) > mode.line_length or len(last) > mode.line_length:
+    if width(first) > mode.line_length or width(last) > mode.line_length:

         return False
 
     # Traverse the AST to examine the context of the multiline string (MLS),
         return False
 
     # Traverse the AST to examine the context of the multiline string (MLS),


@@ -743,7 +793,7 @@ def is_line_short_enough(  # noqa: C901
     # store the leaves that contain parts of the MLS
     multiline_string_contexts: List[LN] = []
 
     # store the leaves that contain parts of the MLS
     multiline_string_contexts: List[LN] = []
 

-    max_level_to_update = math.inf  # track the depth of the MLS
+    max_level_to_update: Union[int, float] = math.inf  # track the depth of the MLS

     for i, leaf in enumerate(line.leaves):
         if max_level_to_update == math.inf:
             had_comma: Optional[int] = None
     for i, leaf in enumerate(line.leaves):
         if max_level_to_update == math.inf:
             had_comma: Optional[int] = None


@@ -830,25 +880,42 @@ def can_be_split(line: Line) -> bool:
 
 
 def can_omit_invisible_parens(
 
 
 def can_omit_invisible_parens(

-    line: Line,
+    rhs: RHSResult,

     line_length: int,
 ) -> bool:
     line_length: int,
 ) -> bool:

-    """Does `line` have a shape safe to reformat without optional parens around it?
+    """Does `rhs.body` have a shape safe to reformat without optional parens around it?

 
     Returns True for only a subset of potentially nice looking formattings but
     the point is to not return false positives that end up producing lines that
     are too long.
     """
 
     Returns True for only a subset of potentially nice looking formattings but
     the point is to not return false positives that end up producing lines that
     are too long.
     """

+    line = rhs.body

     bt = line.bracket_tracker
     if not bt.delimiters:
         # Without delimiters the optional parentheses are useless.
         return True
 
     max_priority = bt.max_delimiter_priority()
     bt = line.bracket_tracker
     if not bt.delimiters:
         # Without delimiters the optional parentheses are useless.
         return True
 
     max_priority = bt.max_delimiter_priority()

-    if bt.delimiter_count_with_priority(max_priority) > 1:
+    delimiter_count = bt.delimiter_count_with_priority(max_priority)
+    if delimiter_count > 1:

         # With more than one delimiter of a kind the optional parentheses read better.
         return False
 
         # With more than one delimiter of a kind the optional parentheses read better.
         return False
 

+    if delimiter_count == 1:
+        if (
+            Preview.wrap_multiple_context_managers_in_parens in line.mode
+            and max_priority == COMMA_PRIORITY
+            and rhs.head.is_with_or_async_with_stmt
+        ):
+            # For two context manager with statements, the optional parentheses read
+            # better. In this case, `rhs.body` is the context managers part of
+            # the with statement. `rhs.head` is the `with (` part on the previous
+            # line.
+            return False
+        # Otherwise it may also read better, but we don't do it today and requires
+        # careful considerations for all possible cases. See
+        # https://github.com/psf/black/issues/2156.
+

     if max_priority == DOT_PRIORITY:
         # A single stranded method call doesn't require optional parentheses.
         return True
     if max_priority == DOT_PRIORITY:
         # A single stranded method call doesn't require optional parentheses.
         return True