Handle ternaries in Style/SafeNavigation

changelog/change_safe_navigation_to_handle_ternaries.md

@@ -0,0 +1 @@
+* [#11116](https://github.com/rubocop/rubocop/issues/11116): Handle ternaries in `Style/SafeNavigation`. ([@fatkodima][])

lib/rubocop/cop/style/redundant_sort.rb

@@ -184,7 +184,7 @@ def arg_node(node)
         end
 
         def arg_value(node)
-          arg_node(node).nil? ? nil : arg_node(node).node_parts.first
+          arg_node(node)&.node_parts&.first
         end
 
         # This gets the start of the accessor whether it has a dot

lib/rubocop/cop/style/safe_navigation.rb

@@ -50,6 +50,11 @@ module Style
       #   foo && foo.bar { |e| e.something }
       #   foo && foo.bar(param) { |e| e.something }
       #
+      #   foo ? foo.bar : nil
+      #   foo.nil? ? nil : foo.bar
+      #   !foo.nil? ? foo.bar : nil
+      #   !foo ? nil : foo.bar
+      #
       #   # good
       #   foo&.bar
       #   foo&.bar&.baz
@@ -105,6 +110,17 @@ class SafeNavigation < Base
           }
         PATTERN
 
+        # @!method ternary_safe_navigation_candidate(node)
+        def_node_matcher :ternary_safe_navigation_candidate, <<~PATTERN
+          {
+            (if (send $_ {:nil? :!}) nil $_)
+
+            (if (send (send $_ :nil?) :!) $_ nil)
+
+            (if $_ $_ nil)
+          }
+        PATTERN
+
         # @!method not_nil_check?(node)
         def_node_matcher :not_nil_check?, '(send (send $_ :nil?) :!)'
 
@@ -118,9 +134,11 @@ def on_and(node)
           check_node(node)
         end
 
+        private
+
         def check_node(node)
           checked_variable, receiver, method_chain, method = extract_parts(node)
-          return unless receiver == checked_variable
+          return if receiver != checked_variable || receiver.nil?
           return if use_var_only_in_unless_modifier?(node, checked_variable)
           return if chain_length(method_chain, method) > max_chain_length
           return if unsafe_method_used?(method_chain, method)
@@ -133,10 +151,8 @@ def use_var_only_in_unless_modifier?(node, variable)
           node.if_type? && node.unless? && !method_called?(variable)
         end
 
-        private
-
         def autocorrect(corrector, node)
-          body = node.node_parts[1]
+          body = extract_body(node)
           method_call = method_call(node)
 
           corrector.remove(begin_range(node, body))
@@ -147,6 +163,14 @@ def autocorrect(corrector, node)
           add_safe_nav_to_all_methods_in_chain(corrector, method_call, body)
         end
 
+        def extract_body(node)
+          if node.if_type? && node.ternary?
+            node.branches.find { |branch| !branch.nil_type? }
+          else
+            node.node_parts[1]
+          end
+        end
+
         def handle_comments(corrector, node, method_call)
           comments = comments(node)
           return if comments.empty?
@@ -174,7 +198,7 @@ def relevant_comment_ranges(node)
         end
 
         def allowed_if_condition?(node)
-          node.else? || node.elsif? || node.ternary?
+          node.else? || node.elsif?
         end
 
         def method_call(node)
@@ -192,7 +216,12 @@ def extract_parts(node)
         end
 
         def extract_parts_from_if(node)
-          variable, receiver = modifier_if_safe_navigation_candidate(node)
+          variable, receiver =
+            if node.ternary?
+              ternary_safe_navigation_candidate(node)
+            else
+              modifier_if_safe_navigation_candidate(node)
+            end
 
           checked_variable, matching_receiver, method = extract_common_parts(receiver, variable)
 

lib/rubocop/cop/variable_force/assignment.rb

@@ -83,7 +83,7 @@ def operator_assignment_node
         end
 
         def multiple_assignment_node
-          grandparent_node = node.parent ? node.parent.parent : nil
+          grandparent_node = node.parent&.parent
           return nil unless grandparent_node
           return nil unless grandparent_node.type == MULTIPLE_ASSIGNMENT_TYPE
           return nil unless node.parent.type == MULTIPLE_LEFT_HAND_SIDE_TYPE

spec/rubocop/cop/style/safe_navigation_spec.rb

@@ -743,11 +743,37 @@ def foobar
       end
 
       context 'ternary expression' do
-        it 'allows ternary expression' do
+        it 'allows non-convertible ternary expression' do
           expect_no_offenses(<<~RUBY)
             !#{variable}.nil? ? #{variable}.bar : something
           RUBY
         end
+
+        it 'registers an offense for convertible ternary expressions' do
+          expect_offense(<<~RUBY, variable: variable)
+            %{variable} ? %{variable}.bar : nil
+            ^{variable}^^^^{variable}^^^^^^^^^^ Use safe navigation (`&.`) instead [...]
+
+            %{variable}.nil? ? nil : %{variable}.bar
+            ^{variable}^^^^^^^^^^^^^^^{variable}^^^^ Use safe navigation (`&.`) instead [...]
+
+            !%{variable}.nil? ? %{variable}.bar : nil
+            ^^{variable}^^^^^^^^^^{variable}^^^^^^^^^ Use safe navigation (`&.`) instead [...]
+
+            !%{variable} ? nil : %{variable}.bar
+            ^^{variable}^^^^^^^^^^{variable}^^^^ Use safe navigation (`&.`) instead [...]
+          RUBY
+
+          expect_correction(<<~RUBY)
+            #{variable}&.bar
+
+            #{variable}&.bar
+
+            #{variable}&.bar
+
+            #{variable}&.bar
+          RUBY
+        end
       end
     end