Introduce RuboCop::Ast::MethodDispatchNode#selector

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master (unreleased)
 
+* [#262](https://github.com/rubocop/rubocop-ast/pull/267): Introduce RuboCop::Ast::MethodDispatchNode#selector. ([@gsamokovarov][])
+
 ## 1.28.1 (2023-05-01)
 
 ### Bug fixes
@@ -416,4 +418,4 @@
 [@gsamokovarov]: https://github.com/gsamokovarov
 [@nobuyo]: https://github.com/nobuyo
 [@tdeo]: https://github.com/tdeo
-[@ydah]: https://github.com/ydah
+[@ydah]: https://github.com/ydah

lib/rubocop/ast/node/mixin/method_dispatch_node.rb

@@ -5,7 +5,7 @@ module AST
     # Common functionality for nodes that are a kind of method dispatch:
     # `send`, `csend`, `super`, `zsuper`, `yield`, `defined?`,
     # and (modern only): `index`, `indexasgn`, `lambda`
-    module MethodDispatchNode
+    module MethodDispatchNode # rubocop:disable Metrics/ModuleLength
       extend NodePattern::Macros
       include MethodIdentifierPredicates
 
@@ -28,6 +28,17 @@ def method_name
         node_parts[1]
       end
 
+      # The source range for the method name or keyword that dispatches this call.
+      #
+      # @return [Parser::Source::Range] the source range for the method name or keyword
+      def selector
+        if loc.respond_to? :keyword
+          loc.keyword
+        else
+          loc.selector
+        end
+      end
+
       # The `block` or `numblock` node associated with this method dispatch, if any.
       #
       # @return [BlockNode, nil] the `block` or `numblock` node associated with this method
@@ -147,7 +158,7 @@ def const_receiver?
       #
       # @return [Boolean] whether the method is the implicit form of `#call`
       def implicit_call?
-        method?(:call) && !loc.selector
+        method?(:call) && !selector
       end
 
       # Whether this method dispatch has an explicit block.
@@ -222,9 +233,9 @@ def lambda_literal?
       #
       # @return [Boolean] whether this method is a unary operation
       def unary_operation?
-        return false unless loc.selector
+        return false unless selector
 
-        operator_method? && loc.expression.begin_pos == loc.selector.begin_pos
+        operator_method? && loc.expression.begin_pos == selector.begin_pos
       end
 
       # Checks whether this is a binary operation.
@@ -235,9 +246,9 @@ def unary_operation?
       #
       # @return [Boolean] whether this method is a binary operation
       def binary_operation?
-        return false unless loc.selector
+        return false unless selector
 
-        operator_method? && loc.expression.begin_pos != loc.selector.begin_pos
+        operator_method? && loc.expression.begin_pos != selector.begin_pos
       end
 
       private

spec/rubocop/ast/super_node_spec.rb

@@ -31,6 +31,12 @@
     it { expect(super_node.method_name).to eq(:super) }
   end
 
+  describe '#selector' do
+    let(:source) { 'super(foo)' }
+
+    it { expect(super_node.selector.source).to eq('super') }
+  end
+
   describe '#method?' do
     context 'when message matches' do
       context 'when argument is a symbol' do

spec/rubocop/ast/yield_node_spec.rb

@@ -23,6 +23,12 @@
     it { expect(yield_node.method_name).to eq(:yield) }
   end
 
+  describe '#selector' do
+    let(:source) { 'yield :foo, :bar' }
+
+    it { expect(yield_node.selector.source).to eq('yield') }
+  end
+
   describe '#method?' do
     context 'when message matches' do
       context 'when argument is a symbol' do