content_script.js

/*
 * (c) Devanshu Raj
 */

let styleSheet = `
	.copyBtn{
		border : 1px solid black;
		border-radius : 3px;
		background : #e6e6e6;
		color : #0f0f0f;
		padding : 5px;
		display : inline-block;
		margin-left : 40px;
		font-size : 0.8rem;
		font-weight : bold;	
	}
`;

let style = document.createElement('style');
style.type = 'text/css';
style.innerHTML = styleSheet;
(document.head || document.documentElement).appendChild(style);

window.addEventListener('load', function () {
  function copyTest(test) {
    let btn = document.createElement('button');
    btn.className = 'copyBtn';
    btn.innerHTML = 'Copy';
    btn.onclick = () => {
      window.navigator.clipboard.writeText(test.lastChild.innerText);
    };

    let head = document.getElementById(test.previousElementSibling.id);
    if (!head) {
      test.insertBefore(document.createElement('br'), test.childNodes[0]);
      test.insertBefore(btn, test.childNodes[0]);
    }

    if (head) head.appendChild(btn);
  }

  let tests = document.getElementsByTagName('pre');

  for (let test of tests) {
    copyTest(test);
  }
});