Function injectCss

test/helpers.ts:4–20

(rules: string)

let seen: string[] = [];

export function injectCss(rules: string) {
  if (seen.indexOf(rules) !== -1) {
    return;
  }

  style =
    style ||
    (function iife() {
      const _style = document.createElement('style');
      _style.appendChild(document.createTextNode(''));
      document.head.appendChild(_style);
      return _style;
    })();

  seen.push(rules);
  style.innerHTML += `\n${rules}`;
}

injectCss.reset = () => {
  if (style) {