Remove empty lines before docstrings in async functions

src/black/lines.py

@@ -24,7 +24,6 @@
     TEST_DESCENDANTS,
     child_towards,
     is_docstring,
-    is_funcdef,
     is_import,
     is_multiline_string,
     is_one_sequence_between,
@@ -709,12 +708,7 @@ def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
             Preview.allow_empty_first_line_in_block in current_line.mode
             and (
                 not is_docstring(current_line.leaves[0], current_line.mode)
-                or (
-                    self.previous_line
-                    and self.previous_line.leaves[0]
-                    and self.previous_line.leaves[0].parent
-                    and not is_funcdef(self.previous_line.leaves[0].parent)
-                )
+                or (self.previous_line and not self.previous_line.is_def)
             )
         )
 

src/black/nodes.py

@@ -742,10 +742,6 @@ def is_multiline_string(leaf: Leaf) -> bool:
     return has_triple_quotes(leaf.value) and "\n" in leaf.value
 
 
-def is_funcdef(node: Node) -> bool:
-    return node.type == syms.funcdef
-
-
 def is_function_or_class(node: Node) -> bool:
     return node.type in {syms.funcdef, syms.classdef, syms.async_funcdef}
 

tests/data/cases/preview_allow_empty_first_line.py

@@ -62,6 +62,17 @@ def method(self):
 
         pass
 
+
+async def async_fn():
+
+    """Docstring."""
+
+
+@decorated
+async def async_fn():
+
+    """Docstring."""
+
 # output
 
 def foo():
@@ -126,3 +137,12 @@ class Cls:
     def method(self):
 
         pass
+
+
+async def async_fn():
+    """Docstring."""
+
+
+@decorated
+async def async_fn():
+    """Docstring."""