<!DOCTYPE HTML>
<html>
<head>
  <title>Test for multiple submissions in straightline code</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
</head>
<body>
<script>

add_task(async function double_submit() {
  dump("test start\n");
  let popup = window.open("file_double_submit.html");
  await new Promise(resolve => {
    popup.addEventListener("load", resolve, {once: true})
  });

  let numCalls = 0;
  popup.addEventListener("beforeunload", () => {
    numCalls++;
    info("beforeunload called " + numCalls + " times");
  });

  info("clicking button");
  popup.document.querySelector("button").click();

  is(numCalls, 1, "beforeunload should only fire once");
  popup.close();
});

</script>
</body>
</html>
