Merge branch 'main' into psfgh-4220

docs/conf.py

@@ -15,10 +15,9 @@
 
 import os
 import string
+from importlib.metadata import version
 from pathlib import Path
 
-from pkg_resources import get_distribution
-
 CURRENT_DIR = Path(__file__).parent
 
 
@@ -43,7 +42,7 @@ def make_pypi_svg(version: str) -> None:
 
 # Autopopulate version
 # The version, including alpha/beta/rc tags, but not commit hash and datestamps
-release = get_distribution("black").version.split("+")[0]
+release = version("black").split("+")[0]
 # The short X.Y version.
 version = release
 for sp in "abcfr":

docs/the_black_code_style/current_style.md

@@ -166,44 +166,35 @@ that in-function vertical whitespace should only be used sparingly.
 _Black_ will allow single empty lines inside functions, and single and double empty
 lines on module level left by the original editors, except when they're within
 parenthesized expressions. Since such expressions are always reformatted to fit minimal
-space, this whitespace is lost. The other exception is that it will remove any empty
-lines immediately following a statement that introduces a new indentation level.
+space, this whitespace is lost.
 
 ```python
 # in:
 
-def foo():
+def function(
+    some_argument: int,
 
-    print("All the newlines above me should be deleted!")
+    other_argument: int = 5,
+) -> EmptyLineInParenWillBeDeleted:
 
 
-if condition:
 
-    print("No newline above me!")
-
-    print("There is a newline above me, and that's OK!")
-
-
-class Point:
-
-    x: int
-    y: int
+    print("One empty line above me will be kept!")
 
+def this_is_okay_too():
+    print("No empty line here")
 # out:
 
-def foo():
-    print("All the newlines above me should be deleted!")
-
-
-if condition:
-    print("No newline above me!")
+def function(
+    some_argument: int,
+    other_argument: int = 5,
+) -> EmptyLineInParenWillBeDeleted:
 
-    print("There is a newline above me, and that's OK!")
+    print("One empty line above me will be kept!")
 
 
-class Point:
-    x: int
-    y: int
+def this_is_okay_too():
+    print("No empty line here")
 ```
 
 It will also insert proper spacing before and after function definitions. It's one line

src/black/linegen.py

@@ -1136,6 +1136,14 @@ def _get_last_non_comment_leaf(line: Line) -> Optional[int]:
     return None
 
 
+def _can_add_trailing_comma(leaf: Leaf, features: Collection[Feature]) -> bool:
+    if is_vararg(leaf, within={syms.typedargslist}):
+        return Feature.TRAILING_COMMA_IN_DEF in features
+    if is_vararg(leaf, within={syms.arglist, syms.argument}):
+        return Feature.TRAILING_COMMA_IN_CALL in features
+    return True
+
+
 def _safe_add_trailing_comma(safe: bool, delimiter_priority: int, line: Line) -> Line:
     if (
         safe
@@ -1160,20 +1168,21 @@ def delimiter_split(
     If the appropriate Features are given, the split will add trailing commas
     also in function signatures and calls that contain `*` and `**`.
     """
-    try:
-        last_leaf = line.leaves[-1]
-    except IndexError:
+    if len(line.leaves) == 0:
         raise CannotSplit("Line empty") from None
+    last_leaf = line.leaves[-1]
 
     bt = line.bracket_tracker
     try:
         delimiter_priority = bt.max_delimiter_priority(exclude={id(last_leaf)})
     except ValueError:
         raise CannotSplit("No delimiters found") from None
 
-    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")
+    if (
+        delimiter_priority == DOT_PRIORITY
+        and bt.delimiter_count_with_priority(delimiter_priority) == 1
+    ):
+        raise CannotSplit("Splitting a single attribute from its owner looks wrong")
 
     current_line = Line(
         mode=line.mode, depth=line.depth, inside_brackets=line.inside_brackets
@@ -1212,15 +1221,8 @@ def append_comments(leaf: Leaf) -> Iterator[Line]:
             yield from append_comments(leaf)
 
         lowest_depth = min(lowest_depth, leaf.bracket_depth)
-        if leaf.bracket_depth == lowest_depth:
-            if is_vararg(leaf, within={syms.typedargslist}):
-                trailing_comma_safe = (
-                    trailing_comma_safe and Feature.TRAILING_COMMA_IN_DEF in features
-                )
-            elif is_vararg(leaf, within={syms.arglist, syms.argument}):
-                trailing_comma_safe = (
-                    trailing_comma_safe and Feature.TRAILING_COMMA_IN_CALL in features
-                )
+        if trailing_comma_safe and leaf.bracket_depth == lowest_depth:
+            trailing_comma_safe = _can_add_trailing_comma(leaf, features)
 
         if last_leaf.type == STANDALONE_COMMENT and leaf_idx == last_non_comment_leaf:
             current_line = _safe_add_trailing_comma(