[Fix rubocop#10401] Fix a false positive for Style/HashSyntax

Fixes rubocop#10401.

This PR fixes a false positive for `Style/HashSyntax`
when local variable hash key and hash value are the same.

changelog/fix_a_false_positive_for_style_hash_syntax.md

@@ -0,0 +1 @@
+* [#10401](https://github.com/rubocop/rubocop/issues/10401): Fix a false positive for `Style/HashSyntax` when local variable hash key and hash value are the same. ([@koic][])

lib/rubocop/cop/mixin/hash_shorthand_syntax.rb

@@ -41,7 +41,7 @@ def enforced_shorthand_syntax
       end
 
       def require_hash_value?(hash_key_source, node)
-        return true if require_hash_value_for_around_hash_literal?(node)
+        return true if !node.key.sym_type? || require_hash_value_for_around_hash_literal?(node)
 
         hash_value = node.value
         return true unless hash_value.send_type? || hash_value.lvar_type?

spec/rubocop/cop/style/hash_syntax_spec.rb

@@ -959,6 +959,19 @@ def do_something
         RUBY
       end
 
+      it 'does not register an offense when method call hash key and hash value are the same' do
+        expect_no_offenses(<<~RUBY)
+          {foo => foo}
+        RUBY
+      end
+
+      it 'does not register an offense when lvar hash key and hash value are the same' do
+        expect_no_offenses(<<~RUBY)
+          foo = 42
+          {foo => foo}
+        RUBY
+      end
+
       it 'does not register an offense when without parentheses call expr follows' do
         # Prevent syntax errors shown in the URL: https://bugs.ruby-lang.org/issues/18396
         expect_no_offenses(<<~RUBY)