<!DOCTYPE html>
<html>
    <head>
        <meta name='viewport' content='initial-scale=1'>
        <script>
            function imageOverlaysAsText()
            {
                const result = [];
                for (const image of Array.from(document.images)) {
                    const root = internals.shadowRoot(image);
                    if (!root)
                        continue;

                    const overlay = root.getElementById("image-overlay");
                    if (!overlay)
                        continue;

                    result.push(overlay.textContent);
                }
                return result;
            }

            function appendImage(imageSource)
            {
                const image = document.createElement("img");
                image.src = imageSource;
                document.body.appendChild(image);
            }

            async function appendAndLoadSubframe(source)
            {
                const frame = document.createElement("iframe");
                frame.src = source;
                await new Promise(resolve => {
                    frame.addEventListener("load", resolve);
                    document.body.appendChild(frame);
                });
            }

            function hideAllImages()
            {
                Array.from(document.images).forEach(image => image.style.setProperty("display", "none"));
            }

            function showAllImages()
            {
                Array.from(document.images).forEach(image => image.style.removeProperty("display"));
            }
        </script>
    </head>
    <body style='margin: 0px;'>
        <p>large-red-square.png</p>
        <img src="large-red-square.png">
        <p>sunset-in-cupertino-200px.png</p>
        <img src="sunset-in-cupertino-200px.png">
        <p>test.jpg</p>
        <img src="test.jpg">
        <p>400x400-green.png</p>
        <img src="400x400-green.png">
        <p>sunset-in-cupertino-100px.tiff</p>
        <img src="sunset-in-cupertino-100px.tiff">
    </body>
</html>