featureString);
    }, `features "${feature}" should NOT set "height=404"`);
  });

  // Codepoints that are valid ASCII digits should be collected
  // Non-ASCII digits and subsequent code points are ignored
  [ 'innerheight=405.5',
    'innerheight=405.32',
    'innerheight=405LLl',
    'innerheight=405^4',
    'innerheight=405*3',
    'innerheight=405/5',
    'innerheight=405  ',
    'innerheight=405e1',
    'innerheight=405e-1'
  ].forEach(feature => {
    async_test(t => {
      var prefixedMessage = n