<!DOCTYPE html>
<meta charset="utf-8">
<meta name="timeout" content="long">
<title>NDEFReader.onreading respect page visibility changes</title>
<link rel="help" href="https://w3c.github.io/web-nfc/#visible-document">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/nfc-helpers.js"></script>
<script>

nfc_test(async (t, mockNFC) => {
  mockNFC.simulateClosedPipe();
  const reader = new NDEFReader();
  const readerWatcher = new EventWatcher(t, reader, ["reading", "error"]);
  const promise = readerWatcher.wait_for("reading").then(event => {
    if (document.hidden) reject();
    resolve();
  });
  await reader.scan();
  await promise;
}, "Test NDEFReader.onreading is not fired when document is hidden");

</script>

<p>Step1: switch the page to the background, then tap a formatted NFC tag.</p>
<p>Step2: switch back to the page, then tap the tag again.</p>