pageinit.back

//Just for backup to refer later

this.page.addInitScript(`{
        const _promiseConstructor = window.Promise.constructor;
        const _timeoutIds = new Set();
        const _setTimeout = window.setTimeout;
        const _clearTimeout = window.clearTimeout;
  
        new MutationObserver(() => {
          window.__pwBusy__("dom++");
          requestAnimationFrame(() => { window.__pwBusy__("dom--"); });
        }).observe(document, { attributes: true, childList: true, subtree: true });
  
        // Patch Promise constructor
        window.Promise.constructor = async (resolve, reject) => {
          window.__pwBusy__("promises++");
  
          const res = resolve && (async () => {
            let val;
            try {
              val = await resolve();
            } catch(err) {
              throw err;
            } finally {
              window.__pwBusy__("promises--");
            }
            return val;
          });
  
          const rej = reject && (async () => {
            let val;
            try {
              val = await reject();
            } catch(err) {
              throw err;
            } finally {
              window.__pwBusy__("promises--");
            }
            return val;
          });
  
          return _promiseConstructor.call(this, res, rej);
        };
  
        // Path window.clearTimeout
        window.clearTimeout = (id) => {
          _clearTimeout(id);
          if (_timeoutIds.has(id)) {
            _timeoutIds.delete(id);
            window.__pwBusy__("timeouts--");
          }
        };
        // Patch window.setTimeout in the near future
        window.setTimeout = (...args) => {
          const ms = args[1];
          const isInNearFuture = ms < 1000 * 5;
          if (isInNearFuture) {
            window.__pwBusy__("timeouts++");
            const fn = args[0];
            if (typeof(fn) === "function") {
              args[0]  = () => {
                try {
                  fn();
                } catch(err) {
                } finally {
                  window.__pwBusy__("timeouts--");
                }
              };
            } else {
              args[0]  = "try{" + args[0] + "; }catch(err){};window.__pwBusy__('timeouts--');";
            }
          }
  
          const timeoutId = _setTimeout.apply(this, args);
  
          if (isInNearFuture) {
            _timeoutIds.add(timeoutId);
          }
  
          return timeoutId;
        };
    }`);