lid.
    { src: 'local(), local(initial)', valid: false },
    { src: 'local("textfont") format(opentype), local("emoji") tech(color-COLRv0)', valid: false },
    { src: 'local(), /*empty*/, url(should be quoted.ttf), junk', valid: false },
    { src: 'url(foo.ttf) format(unknown), url(bar.ttf) tech(broken)', valid: false },
    { src: 'url(foo.ttf) tech(color-COLRv0) otherfunc(othervalue), junk', valid: false },
  ];

  for (let t of tests) {
    test(() => {
      assert_equals(sheet.cssRules.length, 0, "