Anonymous kwargs

Author: kddnewton

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 
 ## [Unreleased]
 
+### Changed
+
+- Support forwarding anonymous keyword arguments with `**`.
+
 ## [5.0.1] - 2022-11-10
 
 ### Changed

lib/syntax_tree/node.rb

@@ -1604,7 +1604,7 @@ def format_contents(q)
   #     { **pairs }
   #
   class AssocSplat < Node
-    # [untyped] the expression that is being splatted
+    # [nil | untyped] the expression that is being splatted
     attr_reader :value
 
     # [Array[ Comment | EmbDoc ]] the comments attached to this node
@@ -1643,7 +1643,7 @@ def deconstruct_keys(_keys)
 
     def format(q)
       q.text("**")
-      q.format(value)
+      q.format(value) if value
     end
 
     def ===(other)

lib/syntax_tree/parser.rb

@@ -744,7 +744,7 @@ def on_assoc_splat(value)
 
       AssocSplat.new(
         value: value,
-        location: operator.location.to(value.location)
+        location: operator.location.to((value || operator).location)
       )
     end
 

test/fixtures/assoc_splat.rb

@@ -12,3 +12,7 @@
 }
 -
 { **foo }
+% # >= 3.2.0
+def foo(**)
+  bar(**)
+end