mozilla-release/testing/web-platform/tests/web-share/share-null-manual.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>WebShare Test: Share null and undefined values</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});

        // Expect null to be converted into the string 'null'. On the other
        // hand, undefined should be equivalent to omitting the attribute.
        setupManualShareTest(
            {title: 'null', text: '', url: getAbsoluteUrl('null')});
        callWhenButtonClicked(() => navigator.share(
              {title: null, text: undefined, url: null}));
    </script>
  </body>
</html>