Fold Yield0 into Yield

Author: kddnewton

CHANGELOG.md

@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 - `IfMod` and `UnlessMod` are no longer nodes. Instead, they have been folded into `If` and `Unless`, respectively. The `If` and `Unless` nodes now have a `modifier?` method to tell you if they were original found in the modifier form.
 - `WhileMod` and `UntilMod` are no longer nodes. Instead, they have been folded into `While` and `Until`, respectively. The `While` and `Until` nodes now have a `modifier?` method to tell you if they were originally found in the modifier form.
 - `VarAlias` is no longer a node. Instead it has been folded into the `Alias` node. The `Alias` node now has a `var_alias?` method to tell you if it is aliasing a global variable.
+- `Yield0` is no longer a node. Instead if has been folded into the `Yield` node. The `Yield` node can now have its `arguments` field be `nil`.
 
 ## [4.3.0] - 2022-10-28
 

lib/syntax_tree/node.rb

@@ -5403,7 +5403,7 @@ def ternaryable?(statement)
         case statement
         when Alias, Assign, Break, Command, CommandCall, Heredoc, If, IfOp,
              Lambda, MAssign, Next, OpAssign, RescueMod, Return, Return0, Super,
-             Undef, Unless, Until, VoidStmt, While, Yield, Yield0, ZSuper
+             Undef, Unless, Until, VoidStmt, While, Yield, ZSuper
           # This is a list of nodes that should not be allowed to be a part of a
           # ternary clause.
           false
@@ -5677,7 +5677,7 @@ def format(q)
       force_flat = [
         Alias, Assign, Break, Command, CommandCall, Heredoc, If, IfOp, Lambda,
         MAssign, Next, OpAssign, RescueMod, Return, Return0, Super, Undef,
-        Unless, VoidStmt, Yield, Yield0, ZSuper
+        Unless, VoidStmt, Yield, ZSuper
       ]
 
       if q.parent.is_a?(Paren) || force_flat.include?(truthy.class) ||
@@ -10101,7 +10101,7 @@ def format(q)
   #     yield value
   #
   class Yield < Node
-    # [Args | Paren] the arguments passed to the yield
+    # [nil | Args | Paren] the arguments passed to the yield
     attr_reader :arguments
 
     # [Array[ Comment | EmbDoc ]] the comments attached to this node
@@ -10128,6 +10128,11 @@ def deconstruct_keys(_keys)
     end
 
     def format(q)
+      if arguments.nil?
+        q.text("yield")
+        return
+      end
+
       q.group do
         q.text("yield")
 
@@ -10146,42 +10151,6 @@ def format(q)
     end
   end
 
-  # Yield0 represents the bare +yield+ keyword with no arguments.
-  #
-  #     yield
-  #
-  class Yield0 < Node
-    # [String] the value of the keyword
-    attr_reader :value
-
-    # [Array[ Comment | EmbDoc ]] the comments attached to this node
-    attr_reader :comments
-
-    def initialize(value:, location:)
-      @value = value
-      @location = location
-      @comments = []
-    end
-
-    def accept(visitor)
-      visitor.visit_yield0(self)
-    end
-
-    def child_nodes
-      []
-    end
-
-    alias deconstruct child_nodes
-
-    def deconstruct_keys(_keys)
-      { value: value, location: location, comments: comments }
-    end
-
-    def format(q)
-      q.text(value)
-    end
-  end
-
   # ZSuper represents the bare +super+ keyword with no arguments.
   #
   #     super

lib/syntax_tree/parser.rb

@@ -3896,11 +3896,11 @@ def on_yield(arguments)
     end
 
     # :call-seq:
-    #   on_yield0: () -> Yield0
+    #   on_yield0: () -> Yield
     def on_yield0
       keyword = consume_keyword(:yield)
 
-      Yield0.new(value: keyword.value, location: keyword.location)
+      Yield.new(arguments: nil, location: keyword.location)
     end
 
     # :call-seq:

lib/syntax_tree/visitor.rb

@@ -467,9 +467,6 @@ class Visitor < BasicVisitor
     # Visit a Yield node.
     alias visit_yield visit_child_nodes
 
-    # Visit a Yield0 node.
-    alias visit_yield0 visit_child_nodes
-
     # Visit a ZSuper node.
     alias visit_zsuper visit_child_nodes
 

lib/syntax_tree/visitor/field_visitor.rb

@@ -1060,10 +1060,6 @@ def visit_yield(node)
         end
       end
 
-      def visit_yield0(node)
-        visit_token(node, "yield0")
-      end
-
       def visit_zsuper(node)
         visit_token(node, "zsuper")
       end

test/node_test.rb

@@ -1013,7 +1013,7 @@ def test_yield
     end
 
     def test_yield0
-      assert_node(Yield0, "yield")
+      assert_node(Yield, "yield")
     end
 
     def test_zsuper