[Fix #10456] Fix a false positive for Layout/MultilineMethodCallIndentation

changelog/fix_false_positive_for_layout_multiline_method_call_indentation.md

@@ -0,0 +1 @@
+* [#10456](https://github.com/rubocop/rubocop/issues/10456): Fix a false positive for `Layout/MultilineMethodCallIndentation` when using `EnforcedStyle: indented` with indented assignment method. ([@koic][])

lib/rubocop/cop/mixin/multiline_expression_indentation.rb

@@ -29,7 +29,9 @@ def on_send(node)
       #   b c { block }.            <-- b is indented relative to a
       #   d                         <-- d is indented relative to a
       def left_hand_side(lhs)
-        lhs = lhs.parent while lhs.parent&.send_type? && lhs.parent.loc.dot
+        while lhs.parent&.send_type? && lhs.parent.loc.dot && !lhs.parent.assignment_method?
+          lhs = lhs.parent
+        end
         lhs
       end
 

spec/rubocop/cop/layout/multiline_method_call_indentation_spec.rb

@@ -985,6 +985,15 @@ def foo
               .to_s
         RUBY
       end
+
+      it "accepts indentation of assignment to obj.#{lhs} with newline after =" do
+        expect_no_offenses(<<~RUBY)
+          obj.#{lhs} =
+            int_part
+              .abs
+              .to_s
+        RUBY
+      end
     end
 
     include_examples 'assignment', 'a'