Fix an infinite loop error for Layout/EmptyLineBetweenDefs

CHANGELOG.md

@@ -22,6 +22,7 @@
 ### Bug fixes
 
 * [#8508](https://github.com/rubocop-hq/rubocop/pull/8508): Fix a false positive for `Style/CaseLikeIf` when conditional contains comparison with a class. Mark `Style/CaseLikeIf` as not safe. ([@fatkodima][])
+* [#8618](https://github.com/rubocop-hq/rubocop/issues/8618): Fix an infinite loop error for `Layout/EmptyLineBetweenDefs`. ([@fatkodima][])
 * [#8534](https://github.com/rubocop-hq/rubocop/issues/8534): Fix `Lint/BinaryOperatorWithIdenticalOperands` for binary operators used as unary operators. ([@marcandre][])
 * [#8537](https://github.com/rubocop-hq/rubocop/pull/8537): Allow a trailing comment as a description comment for `Bundler/GemComment`. ([@pocke][])
 * [#8507](https://github.com/rubocop-hq/rubocop/issues/8507): Fix `Style/RescueModifier` to handle parentheses around rescue modifiers. ([@dsavochkin][])

lib/rubocop/cop/layout/empty_line_between_defs.rb

@@ -61,18 +61,19 @@ def check_defs(nodes)
 
           location = nodes.last.loc.keyword.join(nodes.last.loc.name)
           add_offense(location) do |corrector|
-            autocorrect(corrector, nodes.last)
+            autocorrect(corrector, *nodes)
           end
         end
 
-        def autocorrect(corrector, node)
-          prev_def = prev_node(node)
-
+        def autocorrect(corrector, prev_def, node)
           # finds position of first newline
           end_pos = prev_def.loc.end.end_pos
           source_buffer = prev_def.loc.end.source_buffer
           newline_pos = source_buffer.source.index("\n", end_pos)
 
+          # Handle the case when multiple one-liners are on the same line.
+          newline_pos = end_pos + 1 if newline_pos > node.source_range.begin_pos
+
           count = blank_lines_count_between(prev_def, node)
 
           if count > maximum_empty_lines
@@ -116,16 +117,12 @@ def maximum_empty_lines
           Array(cop_config['NumberOfEmptyLines']).last
         end
 
-        def prev_node(node)
-          return nil unless node.sibling_index.positive?
-
-          node.parent.children[node.sibling_index - 1]
-        end
-
         def lines_between_defs(first_def_node, second_def_node)
-          line_range = def_end(first_def_node)..(def_start(second_def_node) - 2)
+          begin_line_num = def_end(first_def_node)
+          end_line_num = def_start(second_def_node) - 2
+          return [] if end_line_num.negative?
 
-          processed_source.lines[line_range]
+          processed_source.lines[begin_line_num..end_line_num]
         end
 
         def def_start(node)

spec/rubocop/cop/layout/empty_line_between_defs_spec.rb

@@ -276,6 +276,19 @@ def o
     RUBY
   end
 
+  it 'registers an offense for multiple one-liners on the same line' do
+    expect_offense(<<~RUBY)
+      def a; end; def b; end
+                  ^^^^^ Use empty lines between method definitions.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      def a; end; 
+
+      def b; end
+    RUBY
+  end
+
   context 'when AllowAdjacentOneLineDefs is enabled' do
     let(:cop_config) { { 'AllowAdjacentOneLineDefs' => true } }