pad.pub0.org/tests/frontend/specs/responsiveness.js

// Test for https://github.com/ether/etherpad-lite/issues/1763

// This test fails in Opera, IE and Safari
// Opera fails due to a weird way of handling the order of execution, yet actual performance seems fine
// Safari fails due the delay being too great yet the actual performance seems fine
// Firefox might panic that the script is taking too long so will fail
// IE will fail due to running out of memory as it can't fit 2M chars in memory.

// Just FYI Google Docs crashes on large docs whilst trying to Save, it's likely the limitations we are
// experiencing are more to do with browser limitations than improper implementation.
// A ueber fix for this would be to have a separate lower cpu priority thread that handles operations that aren't
// visible to the user.

// Adapted from John McLear's original test case.

xdescribe('Responsiveness of Editor', function () {
  // create a new pad before each test run
  beforeEach(function (cb) {
    helper.newPad(cb);
    this.timeout(6000);
  });
  // JM commented out on 8th Sep 2020 for a release, after release this needs uncommenting
  // And the test needs to be fixed to work in Firefox 52 on Windows 7.  I am not sure why it fails on this specific platform
  // The errors show this.timeout... then crash the browser but I am sure something is actually causing the stack trace and
  // I just need to narrow down what, offers to help accepted.
  it('Fast response to keypress in pad with large amount of contents', function (done) {
    // skip on Windows Firefox 52.0
    if (window.bowser && window.bowser.windows && window.bowser.firefox && window.bowser.version == '52.0') {
      this.skip();
    }
    const inner$ = helper.padInner$;
    const chrome$ = helper.padChrome$;
    const chars = '0000000000'; // row of placeholder chars
    const amount = 200000; // number of blocks of chars we will insert
    const length = (amount * (chars.length) + 1); // include a counter for each space
    let text = ''; // the text we're gonna insert
    this.timeout(amount * 150); // Changed from 100 to 150 to allow Mac OSX Safari to be slow.

    // get keys to send
    const keyMultiplier = 10; // multiplier * 10 == total number of key events
    let keysToSend = '';
    for (var i = 0; i <= keyMultiplier; i++) {
      keysToSend += chars;
    }

    const textElement = inner$('div');
    textElement.sendkeys('{selectall}'); // select all
    textElement.sendkeys('{del}'); // clear the pad text

    for (var i = 0; i <= amount; i++) {
      text = `${text + chars} `; // add the chars and space to the text contents
    }
    inner$('div').first().text(text); // Put the text contents into the pad

    helper.waitFor(() => // Wait for the new contents to be on the pad
      inner$('div').text().length > length
    ).done(() => {
      expect(inner$('div').text().length).to.be.greaterThan(length); // has the text changed?
      const start = Date.now(); // get the start time

      // send some new text to the screen (ensure all 3 key events are sent)
      const el = inner$('div').first();
      for (let i = 0; i < keysToSend.length; ++i) {
        var x = keysToSend.charCodeAt(i);
        ['keyup', 'keypress', 'keydown'].forEach((type) => {
          const e = $.Event(type);
          e.keyCode = x;
          el.trigger(e);
        });
      }

      helper.waitFor(() => { // Wait for the ability to process
        const el = inner$('body');
        if (el[0].textContent.length > amount) return true;
      }).done(() => {
        const end = Date.now(); // get the current time
        const delay = end - start; // get the delay as the current time minus the start time

        expect(delay).to.be.below(600);
        done();
      }, 5000);
    }, 10000);
  });
});