Using hx-swap="delete swap:1s", element is possibly deleted

[jackielii]

When using a hx-swap="delete swap:1s", the target element could have been deleted already.

To reproduce simply do:

<div id="add-users-modal" hx-replace>
  <button
		  hx-post="/add"
		  hx-target="#add-users-modal"
		  hx-swap="delete swap:1s"
		  @htmx:after-request="show=false"
		  type="button"
  >add<button>
</div>
<script>
document.addEventListener("htmx:beforeSwap", (event) => {
  const content = event.detail.serverResponse;
  if (content.includes("hx-replace")) {
    const parser = new DOMParser();
    const doc = parser.parseFromString(content, "text/html");
    const id = doc.querySelector("[hx-replace]").id;
    const el = event.detail.target.querySelector(`#${id}`);
    if (el) {
      el.remove();
    }
  }
});
<script>

Here hx-replace is an attribute I defined myself to replace if present else append.

In such use cases, I'll get htmx.esm.js:1699 Uncaught TypeError: Cannot read properties of null (reading 'removeChild')