<!DOCTYPE html>
<title>Test relList attribute</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
let link_support_table = {};
// https://html.spec.whatwg.org/multipage/links.html#linkTypes
link_support_table['link'] = {
  supported : ['modulepreload', 'preload', 'preconnect', 'dns-prefetch',
               'stylesheet', 'icon', 'alternate', 'prefetch',
               'prerender', 'next', 'manifest', 'apple-touch-icon',
               'apple-touch-icon-precomposed', 'canonical'],
  unsupported : ['author', 'bookmark', 'external', 'help', 'import',
                 'license', 'nofollow', 'pingback', 'prev', 'search',
                 'tag', 'noreferrer', 'noopener']
};
link_support_table['a'] =  {
  supported : ['noreferrer', 'noopener', 'opener'],
  unsupported : ['author', 'bookmark', 'external', 'help', 'license',
                 'nofollow', 'pingback', 'prev', 'search', 'tag',
                 'modulepreload', 'preload', 'preconnect', 'dns-prefetch',
                 'stylesheet', 'import', 'icon', 'alternate', 'prefetch',
                 'prerender', 'next', 'manifest', 'apple-touch-icon',
                 'apple-touch-icon-precomposed', 'canonical']
};
link_support_table['area'] = link_support_table['a'];
link_support_table['form'] = link_support_table['a'];

function test_rellist(tag_name) {
  const rel_table = link_support_table[tag_name];
  const element = document.createElement(tag_name);
  let tag = element.tagName;
  // Test that setting rel is also setting relList, for both
  // valid and invalid values.
  element.rel = 'whatever';
  assert_true(element.relList.contains('whatever'), 'tag = ' + tag + ', setting rel must work');
  element.rel = 'prefetch';
  assert_true(element.relList.contains('prefetch'), 'tag = ' + tag + ', setting rel must work');
  // Test that add() works.
  element.relList.add('preloadwhatever');
  assert_equals(element.rel, 'prefetch preloadwhatever', 'tag = ' + tag + ', add must work');
  assert_true(element.relList.contains('preloadwhatever'), 'tag = ' + tag + ', add must work');
  // Test that remove() works.
  element.relList.remove('preloadwhatever');
  assert_equals(element.rel, 'prefetch', 'tag = ' + tag + ', remove must work');
  assert_false(element.relList.contains('preloadwhatever'), 'tag = ' + tag + ', remove must work');
  // Test that toggle() works.
  element.relList.toggle('prefetch', false);
  assert_equals(element.rel, '', 'tag = ' + tag + ', toggle must work');
  element.relList.toggle('prefetch', true);
  assert_equals(element.rel, 'prefetch', 'tag = ' + tag + ', toggle must work');
  // Test that replace() works.
  element.relList.replace('prefetch', 'first');
  assert_equals(element.rel, 'first', 'tag = ' + tag + ', replace must work');
  // Test that indexed item getter works.
  element.relList.add('second');
  assert_equals(element.relList.length, 2, 'tag = ' + tag + ', relList length must be correct');
  assert_equals(element.relList[0], 'first', 'tag = ' + tag + ', relList indexed item must work');
  assert_equals(element.relList[1], 'second', 'tag = ' + tag + ', relList indexed item must work');
  // Test that relList is  [SameObject].
  let savedRelList = element.relList;
  element.rel = 'something';
  assert_equals(element.relList, savedRelList, 'tag = ' + tag + ', SameObject must work');

  // Test that supports() is returning true for valid values
  // and false for invalid ones.
  let supported = rel_table['supported'];
  for (let link_type in supported) {
    assert_true(element.relList.supports(supported[link_type]), 'tag = ' + tag + ', link type = ' + supported[link_type] + ' must be supported');
    assert_true(element.relList.supports(supported[link_type].toUpperCase()), 'tag = ' + tag + ', link type = ' + supported[link_type].toUpperCase() + ' must be supported');
  }
  let unsupported = rel_table['unsupported'];
  for (let link_type in unsupported) {
    assert_false(element.relList.supports(unsupported[link_type]), 'tag = ' + tag + ', link type = ' + unsupported[link_type] + ' must be unsupported');
  }
}

['link', 'a', 'area', 'form'].forEach(tag_name => {
  test(
    () => test_rellist(tag_name),
    `Make sure that relList based feature detection is working for <${tag_name}>`
  );
});
</script>