Make Rails/SaveBang aware of safe navigation operator

Author: hoshinotsuyoshi

lib/rubocop/cop/rails/save_bang.rb

@@ -146,6 +146,7 @@ def on_send(node) # rubocop:disable Metrics/CyclomaticComplexity
 
           add_offense_for_node(node)
         end
+        alias on_csend on_send
 
         def autocorrect(node)
           save_loc = node.loc.selector

spec/rubocop/cop/rails/save_bang_spec.rb

@@ -60,6 +60,16 @@
                 'if the return value is not checked.'])
     end
 
+    context 'when using safe navigation operator', :ruby23 do
+      it "when using #{method} without arguments" do
+        inspect_source("object&.#{method}")
+
+        expect(cop.messages)
+          .to eq(["Use `#{method}!` instead of `#{method}` " \
+        'if the return value is not checked.'])
+      end
+    end
+
     it "when using #{method}!" do
       expect_no_offenses("object.#{method}!")
     end
@@ -77,6 +87,14 @@
 
       expect(new_source).to eq("object.#{method}!()")
     end
+
+    context 'when using safe navigation operator', :ruby23 do
+      it 'autocorrects' do
+        new_source = autocorrect_source("object&.#{method}()")
+
+        expect(new_source).to eq("object&.#{method}!()")
+      end
+    end
   end
 
   shared_examples 'checks_variable_return_use_offense' do |method, update|