[Fix #4723] RaiseArgs shouldn't autocorrect 3-args form (#4725)

Author: smakagon

CHANGELOG.md

@@ -69,6 +69,7 @@
 * [#4593](https://github.com/bbatsov/rubocop/issues/4593): Fix false positive in `Rails/SaveBang` when `save/update_attribute` is used with a `case` statement. ([@theRealNG][])
 * [#4322](https://github.com/bbatsov/rubocop/issues/4322): Fix Style/MultilineMemoization from autocorrecting to invalid ruby. ([@dpostorivo][])
 * [#4722](https://github.com/bbatsov/rubocop/pull/4722): Fix `rake new_cop` problem that doesn't add `require` line. ([@koic][])
+* [#4723](https://github.com/bbatsov/rubocop/issues/4723): Fix `RaiseArgs` auto-correction issue for `raise` with 3 arguments. ([@smakagon][])
 
 ### Changes
 

lib/rubocop/cop/style/raise_args.rb

@@ -60,33 +60,32 @@ def on_send(node)
         private
 
         def autocorrect(node)
-          new_exception = if style == :compact
-                            correction_exploded_to_compact(node.arguments)
-                          else
-                            correction_compact_to_exploded(node.first_argument)
-                          end
-          replacement = "#{node.method_name} #{new_exception}"
+          replacement = if style == :compact
+                          correction_exploded_to_compact(node)
+                        else
+                          correction_compact_to_exploded(node)
+                        end
 
           ->(corrector) { corrector.replace(node.source_range, replacement) }
         end
 
         def correction_compact_to_exploded(node)
-          exception_node, _new, message_node = *node
+          exception_node, _new, message_node = *node.first_argument
 
           message = message_node && message_node.source
 
           correction = exception_node.const_name.to_s
           correction = "#{correction}, #{message}" if message
 
-          correction
+          "#{node.method_name} #{correction}"
         end
 
         def correction_exploded_to_compact(node)
-          exception_node, *message_nodes = *node
+          exception_node, *message_nodes = *node.arguments
+          return node.source if message_nodes.size > 1
 
-          messages = message_nodes.map(&:source).join(', ')
-
-          "#{exception_node.const_name}.new(#{messages})"
+          argument = message_nodes.first.source
+          "#{node.method_name} #{exception_node.const_name}.new(#{argument})"
         end
 
         def check_compact(node)

spec/rubocop/cop/style/raise_args_spec.rb

@@ -61,9 +61,11 @@
         RUBY
       end
 
-      it 'auto-corrects to compact style' do
-        new_source = autocorrect_source(['raise RuntimeError, msg, caller'])
-        expect(new_source).to eq('raise RuntimeError.new(msg, caller)')
+      it 'does not auto-correct to compact style' do
+        initial_source = 'raise RuntimeError, msg, caller'
+
+        new_source = autocorrect_source([initial_source])
+        expect(new_source).to eq(initial_source)
       end
     end