mozilla-release/testing/web-platform/tests/web-share/share-extra-field-manual.https.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>WebShare Test: Surplus fields ignored</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="resources/manual-helper.js"></script>
  </head>
  <body>
    <script>
        setup({explicit_timeout: true});

        setupManualShareTest(
            {title: 'the title', text: 'the message', url: 'https://example.com'});
        callWhenButtonClicked(() => navigator.share(
              {title: 'the title', text: 'the message', url: 'https://example.com',
               unused: 'unexpected field'}));
    </script>
  </body>
</html>