[Fix #9939] Fix/hash as last array item (#9943)

lib/rubocop/cop/style/hash_as_last_array_item.rb

@@ -29,6 +29,7 @@ module Style
       #   # good
       #   [{ one: 1 }, { two: 2 }]
       class HashAsLastArrayItem < Base
+        include RangeHelp
         include ConfigurableEnforcedStyle
         extend AutoCorrector
 
@@ -74,6 +75,7 @@ def check_no_braces(node)
           return if node.children.empty? # Empty hash cannot be "unbraced"
 
           add_offense(node, message: 'Omit the braces around the hash.') do |corrector|
+            remove_last_element_trailing_comma(corrector, node.parent)
             corrector.remove(node.loc.begin)
             corrector.remove(node.loc.end)
           end
@@ -82,6 +84,15 @@ def check_no_braces(node)
         def braces_style?
           style == :braces
         end
+
+        def remove_last_element_trailing_comma(corrector, node)
+          range = range_with_surrounding_space(
+            range: node.children.last.source_range,
+            side: :right
+          ).end.resize(1)
+
+          corrector.remove(range) if range.source == ','
+        end
       end
     end
   end

spec/rubocop/cop/style/hash_as_last_array_item_spec.rb

@@ -54,6 +54,55 @@
       RUBY
     end
 
+    it 'registers an offense and corrects when hash with braces and trailing comma' do
+      expect_offense(<<~RUBY)
+        [1, 2, { one: 1, two: 2, },]
+               ^^^^^^^^^^^^^^^^^^^ Omit the braces around the hash.
+      RUBY
+
+      expect_correction(<<~RUBY)
+        [1, 2,  one: 1, two: 2, ]
+      RUBY
+    end
+
+    it 'registers an offense and corrects when hash with braces and trailing comma and new line' do
+      expect_offense(<<~RUBY)
+        [
+          1,
+          2,
+          {
+          ^ Omit the braces around the hash.
+            one: 1,
+            two: 2,
+          },
+        ]
+      RUBY
+
+      expect_correction(<<~RUBY)
+        [
+          1,
+          2,
+        #{'  '}
+            one: 1,
+            two: 2,
+        #{'  '}
+        ]
+      RUBY
+    end
+
+    it 'does not register an offense when hash is not the last element' do
+      expect_no_offenses(<<~RUBY)
+        [
+          1,
+          2,
+          {
+            one: 1
+          },
+          two: 2
+        ]
+      RUBY
+    end
+
     it 'does not register an offense when hash without braces' do
       expect_no_offenses(<<~RUBY)
         [1, 2, one: 1, two: 2]