Add on_after_<type> callbacks

I doubled check that this has basically no performance impact (less than ~0.1% overall) after #8882

CHANGELOG.md

@@ -12,6 +12,7 @@
 * [#8892](https://github.com/rubocop-hq/rubocop/issues/8892): Fix an error for `Style/StringConcatenation` when correcting nested concatenable parts. ([@fatkodima][])
 * [#8781](https://github.com/rubocop-hq/rubocop/issues/8781): Fix handling of comments in `Style/SafeNavigation` autocorrection. ([@dvandersluis][])
 * [#8907](https://github.com/rubocop-hq/rubocop/pull/8907): Fix an incorrect auto-correct for `Layout/ClassStructure` when heredoc constant is defined after public method. ([@koic][])
+* [#8889](https://github.com/rubocop-hq/rubocop/pull/8889): Cops can use new `after_<type>` callbacks (only for nodes that may have children nodes, like `:send` and unlike `:sym`). ([@marcandre][])
 
 ### Changes
 

docs/modules/ROOT/pages/development.adoc

@@ -248,6 +248,8 @@ module RuboCop
 end
 ----
 
+Note that `on_send` will be called on a given `node` before the callbacks `on_<some type>` for its children are called. There's also a callback `after_send` that is called after the children are processed. There's a similar `after_<some type>` callback for all types, except those that never have children.
+
 Update the spec to cover the expected syntax:
 
 [source,ruby]

lib/rubocop/cop/base.rb

@@ -271,7 +271,7 @@ def callbacks_needed
       # @api private
       def self.callbacks_needed
         @callbacks_needed ||= public_instance_methods.select do |m|
-          m.match?(/^on_/) &&
+          m.match?(/^on_|^after_/) &&
             !Base.method_defined?(m) # exclude standard "callbacks" like 'on_begin_investigation'
         end
       end

lib/rubocop/cop/commissioner.rb

@@ -7,7 +7,7 @@ module Cop
     class Commissioner
       include RuboCop::AST::Traversal
 
-      RESTRICTED_CALLBACKS = %i[on_send on_csend].freeze
+      RESTRICTED_CALLBACKS = %i[on_send on_csend after_send after_csend].freeze
       private_constant :RESTRICTED_CALLBACKS
 
       # How a Commissioner returns the results of the investigation
@@ -60,16 +60,18 @@ def initialize(cops, forces = [], options = {})
         method_name = :"on_#{node_type}"
         next unless method_defined?(method_name)
 
-        if RESTRICTED_CALLBACKS.include?(method_name)
-          trigger_restricted = "trigger_restricted_cops(:on_#{node_type}, node)"
-        end
+        # Hacky: Comment-out code as needed
+        r = '#' unless RESTRICTED_CALLBACKS.include?(method_name) # has Restricted?
+        c = '#' if NO_CHILD_NODES.include?(node_type) # has Children?
 
         class_eval(<<~RUBY, __FILE__, __LINE__ + 1)
-          def on_#{node_type}(node)
-            trigger_responding_cops(:on_#{node_type}, node)
-            #{trigger_restricted}
-            #{'super(node)' unless NO_CHILD_NODES.include?(node_type)}
-          end
+                  def on_#{node_type}(node)
+                    trigger_responding_cops(:on_#{node_type}, node)
+              #{r}  trigger_restricted_cops(:on_#{node_type}, node)
+          #{c}      super(node)
+          #{c}      trigger_responding_cops(:after_#{node_type}, node)
+          #{c}#{r}  trigger_restricted_cops(:after_#{node_type}, node)
+                  end
         RUBY
       end
 

spec/rubocop/cop/commissioner_spec.rb

@@ -13,6 +13,10 @@ def on_int(node); end
                                     alias_method :on_def, :on_int
                                     alias_method :on_send, :on_int
                                     alias_method :on_csend, :on_int
+                                    alias_method :after_int, :on_int
+                                    alias_method :after_def, :on_int
+                                    alias_method :after_send, :on_int
+                                    alias_method :after_csend, :on_int
                                   end)
     end
     let(:cop) do
@@ -51,6 +55,9 @@ def method
 
     it 'traverses the AST and invoke cops specific callbacks' do
       expect(cop).to receive(:on_def).once
+      expect(cop).to receive(:on_int).once
+      expect(cop).not_to receive(:after_int)
+      expect(cop).to receive(:after_def).once
       offenses
     end
 
@@ -72,7 +79,9 @@ def method
 
         it 'calls on_send for the right method calls' do
           expect(cop).to receive(:on_send).once
+          expect(cop).to receive(:after_send).once
           expect(cop).not_to receive(:on_csend)
+          expect(cop).not_to receive(:after_csend)
           offenses
         end
 
@@ -82,6 +91,8 @@ def method
           it 'calls on_send for the right method calls' do
             expect(cop).to receive(:on_send).once
             expect(cop).to receive(:on_csend).once
+            expect(cop).to receive(:after_send).once
+            expect(cop).to receive(:after_csend).once
             offenses
           end
         end