[Fix #9905] Fix single line concatenation false positive

changelog/fix_line_end_string_concatenation_indentation.md

@@ -0,0 +1 @@
+* [#9905](https://github.com/rubocop/rubocop/issues/9905): Fix false positive for single line concatenation in `Layout/LineEndStringConcatenationIndentation`. ([@jonas054][])

lib/rubocop/cop/layout/line_end_string_concatenation_indentation.rb

@@ -85,14 +85,9 @@ def autocorrect(corrector, node)
         private
 
         def strings_concatenated_with_backslash?(dstr_node)
-          !dstr_node.heredoc? &&
-            !single_string_literal?(dstr_node) &&
-            dstr_node.children.length > 1 &&
-            dstr_node.children.all? { |c| c.str_type? || c.dstr_type? }
-        end
-
-        def single_string_literal?(dstr_node)
-          dstr_node.loc.respond_to?(:begin) && dstr_node.loc.begin
+          dstr_node.multiline? &&
+            dstr_node.children.all? { |c| c.str_type? || c.dstr_type? } &&
+            dstr_node.children.none?(&:multiline?)
         end
 
         def always_indented?(dstr_node)

spec/rubocop/cop/layout/line_end_string_concatenation_indentation_spec.rb

@@ -14,6 +14,21 @@
   let(:cop_indent) { nil } # use indentation width from Layout/IndentationWidth
 
   shared_examples 'common' do
+    it 'accepts single line string literal concatenation' do
+      expect_no_offenses(<<~'RUBY')
+        text = 'offense'
+        puts 'This probably should not be '"an #{text}"
+      RUBY
+    end
+
+    it 'accepts string literal with line break concatenated with other string' do
+      expect_no_offenses(<<~'RUBY')
+        text = 'offense'
+        puts 'This probably
+              should not be '"an #{text}"
+      RUBY
+    end
+
     it 'accepts a multiline string literal' do
       expect_no_offenses(<<~'RUBY')
         puts %(