Fix a false positive for Layout/SingleLineBlockChain

changelog/fix_a_false_positive_for_layout_single_line_block_chain.md

@@ -0,0 +1 @@
+* [#10063](https://github.com/rubocop/rubocop/pull/10063): Fix a false positive for `Layout/SingleLineBlockChain` when method call chained on a new line after a single line block with trailing dot. ([@koic][])

lib/rubocop/cop/layout/single_line_block_chain.rb

@@ -37,15 +37,26 @@ def offending_range(node)
           return unless receiver&.block_type?
 
           receiver_location = receiver.loc
-          closing_block_delimiter_line_number = receiver_location.end.line
-          return if receiver_location.begin.line < closing_block_delimiter_line_number
+          closing_block_delimiter_line_num = receiver_location.end.line
+          return if receiver_location.begin.line < closing_block_delimiter_line_num
 
           node_location = node.loc
           dot_range = node_location.dot
           return unless dot_range
-          return if dot_range.line > closing_block_delimiter_line_number
+          return unless call_method_after_block?(node, dot_range, closing_block_delimiter_line_num)
 
-          range_between(dot_range.begin_pos, node_location.selector.end_pos)
+          range_between(dot_range.begin_pos, selector_range(node).end_pos)
+        end
+
+        def call_method_after_block?(node, dot_range, closing_block_delimiter_line_num)
+          return false if dot_range.line > closing_block_delimiter_line_num
+
+          dot_range.column < selector_range(node).column
+        end
+
+        def selector_range(node)
+          # l.(1) has no selector, so we use the opening parenthesis instead
+          node.loc.selector || node.loc.begin
         end
       end
     end

spec/rubocop/cli/autocorrect_spec.rb

@@ -2070,6 +2070,21 @@ def do_even_more_stuff
     RUBY
   end
 
+  it 'corrects `Layout/DotPosition` and `Layout/SingleLineBlockChain` offenses' do
+    source_file = Pathname('example.rb')
+    create_file(source_file, <<~RUBY)
+      example.select { |item| item.cond? }.
+              join('-')
+    RUBY
+
+    expect(cli.run(['-a', '--only', 'Layout/DotPosition,Layout/SingleLineBlockChain'])).to eq(0)
+
+    expect(source_file.read).to eq(<<~RUBY)
+      example.select { |item| item.cond? }
+              .join('-')
+    RUBY
+  end
+
   it 'does not correct Style/IfUnlessModifier offense disabled by a comment directive and ' \
      'does not fire Lint/RedundantCopDisableDirective offense even though that directive ' \
      'would make the modifier form too long' do

spec/rubocop/cop/layout/single_line_block_chain_spec.rb

@@ -13,13 +13,32 @@
     RUBY
   end
 
+  it 'registers an offense for no selector method call chained on the same line as a block' do
+    expect_offense(<<~RUBY)
+      example.select { |item| item.cond? }.(42)
+                                          ^^ Put method call on a separate line if chained to a single line block.
+    RUBY
+
+    expect_correction(<<~RUBY)
+      example.select { |item| item.cond? }
+      .(42)
+    RUBY
+  end
+
   it 'does not register an offense for method call chained on a new line after a single line block' do
     expect_no_offenses(<<~RUBY)
       example.select { |item| item.cond? }
              .join('-')
     RUBY
   end
 
+  it 'does not register an offense for method call chained on a new line after a single line block with trailing dot' do
+    expect_no_offenses(<<~RUBY)
+      example.select { |item| item.cond? }.
+              join('-')
+    RUBY
+  end
+
   it 'does not register an offense for method call chained without a dot' do
     expect_no_offenses(<<~RUBY)
       example.select { |item| item.cond? } + 2