Only parse target Ruby from gemspec if array elements are strings

changelog/fix_only_parse_target_ruby_from_gemspec_if_array.md

@@ -0,0 +1 @@
+* [#12756](https://github.com/rubocop/rubocop/pull/12756): Only parse target Ruby from gemspec if array elements are strings. ([@davidrunger][])

lib/rubocop/target_ruby.rb

@@ -105,7 +105,7 @@ def version_from_gemspec_file(file)
       def version_from_right_hand_side(right_hand_side)
         gem_requirement_versions = gem_requirement_versions(right_hand_side)
 
-        if right_hand_side.array_type?
+        if right_hand_side.array_type? && right_hand_side.children.all?(&:str_type?)
           version_from_array(right_hand_side)
         elsif gem_requirement_versions
           gem_requirement_versions.map(&:value)

spec/rubocop/target_ruby_spec.rb

@@ -188,10 +188,25 @@
 
       context 'when file reads the required_ruby_version from another file' do
         it 'uses the default target ruby version' do
-          content = <<~HEREDOC
+          content = <<~'HEREDOC'
+            Gem::Specification.new do |s|
+              s.name = 'test'
+              s.required_ruby_version = Gem::Requirement.new(">= #{File.read('.ruby-version').rstrip}")
+              s.licenses = ['MIT']
+            end
+          HEREDOC
+
+          create_file(gemspec_file_path, content)
+          expect(target_ruby.version).to eq default_version
+        end
+      end
+
+      context 'when file reads the required_ruby_version from another file in an array' do
+        it 'uses the default target ruby version' do
+          content = <<~'HEREDOC'
             Gem::Specification.new do |s|
               s.name = 'test'
-              s.required_ruby_version = Gem::Requirement.new(">= \#{File.read('.ruby-version').rstrip}")
+              s.required_ruby_version = [">= #{File.read('.ruby-version').rstrip}"]
               s.licenses = ['MIT']
             end
           HEREDOC