Detect rails as the testing framework if direct dependency on railties

lib/ruby_lsp/global_state.rb

@@ -104,8 +104,10 @@ def detect_test_library
       if direct_dependency?(/^rspec/)
         "rspec"
       # A Rails app may have a dependency on minitest, but we would instead want to use the Rails test runner provided
-      # by ruby-lsp-rails.
-      elsif direct_dependency?(/^rails$/)
+      # by ruby-lsp-rails. A Rails app doesn't need to depend on the rails gem itself, individual components like
+      # activestorage may be added to the gemfile so that other components aren't present. A Rails app doesn't boot
+      # without railties, so check that as well.
+      elsif direct_dependency?(/^rails$/) || direct_dependency?(/^railties$/)
         "rails"
       # NOTE: Intentionally ends with $ to avoid mis-matching minitest-reporters, etc. in a Rails app.
       elsif direct_dependency?(/^minitest$/)

test/global_state_test.rb

@@ -39,6 +39,12 @@ def test_detects_rails_if_both_rails_and_minitest_are_present
       assert_equal("rails", GlobalState.new.test_library)
     end
 
+    def test_detects_rails_if_both_minitest_and_railties_are_present
+      stub_dependencies("minitest" => "1.2.3", "railties" => "1.2.3")
+
+      assert_equal("rails", GlobalState.new.test_library)
+    end
+
     def test_detects_rspec_if_both_rails_and_rspec_are_present
       stub_dependencies("rspec" => "1.2.3", "rails" => "1.2.3")