chromium/chrome/test/data/session_history/soft-navigation-back-page.html

<!--
Copyright 2023 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->

<html>

<head>
  <style>
    #button {
      width: 200px;
      height: 200px;
    }
  </style>
</head>

<body>
  <main>
    <div>This is some content</div>
    <button id="button">Click me!</button>
  </main>
  <script>
    const button = document.getElementById("button");
    let first = true;
    button.addEventListener("click", e => {
      history.back();
      const content = document.createElement("div");
      content.innerHTML = "This is some more content";
      document.getElementsByTagName("main")[0].insertBefore(content, button);
    });
  </script>
</body>

</html>