GitHubWrapper/docs/_static/copy.js

const COPY = "content_copy";
const COPIED = "done";

const copy = async (obj) => {
  // <span class="copy"><span class="material-icons">{{text}}</span></span>
  await navigator.clipboard.writeText(obj.children[1].innerText).then(
    () => {
      let icon = obj.children[0].children[0];
      icon.textContent = COPIED;
      setTimeout(() => (icon.textContent = COPY), 2500);
    },
    (r) => alert('Could not copy codeblock:\n' + r.toString())
  );
};

document.addEventListener("DOMContentLoaded", () => {
  let allCodeblocks = document.querySelectorAll("div[class='highlight']");

  for (let codeblock of allCodeblocks) {
    codeblock.parentNode.className += " relative-copy";
    let copyEl = document.createElement("span");
    copyEl.addEventListener('click', () => copy(codeblock));
    copyEl.className = "copy";
    copyEl.setAttribute("aria-label", "Copy Code");
    copyEl.setAttribute("title", "Copy Code");

    let copyIcon = document.createElement("span");
    copyIcon.className = "material-icons";
    copyIcon.textContent = COPY;
    copyEl.append(copyIcon);

    codeblock.prepend(copyEl);
  }
});