ssert_equals(getComputedStyle(target).columnGap, "normal");
      }, "Negative gap is invalid");
    test(
      function(){
        var target = document.getElementById("invalidGapMaxContent");
        assert_equals(getComputedStyle(target).rowGap, "normal");
        assert_equals(getComputedStyle(target).columnGap, "normal");
      }, "'max-content' gap is invalid");
    test(
      function(){
        var target = document.getElementById("invalidGapNone");
        assert_equals(getComputedStyle(target).r