cypress: Memory leak in long running single test

Current behavior:

Currently if a test runs the same actions repetitively over a long period of time, the memory of the cypress process increases until it crashes. (headless mode, video off, numTestsKeptInMemory 0) The sample to reproduce runs 15 minutes increasing the memory ~300MB. (the longer the run the more memory is used…)

Desired behavior:

Performance tests should be possible with cypress, without increasing memory and crashing.

Steps to reproduce: (app code and test code)

Config cypress.json

{
  "baseUrl": "http://localhost:8080/",
  "defaultCommandTimeout": 60000,
  "viewportWidth": 1280,
  "viewportHeight": 720,
  "numTestsKeptInMemory": 0,
  "video": false
}

Cypress test

describe('memory dummy test', () => {
    const endTime = Date.now() + 60000 * 15;

    before('visit', () => {
        cy.visit('/memory-test.html');
    });

    it('should test', () => {
        const test = () => {
            cy.get('#testinput').clear().type('hello world');
            cy.wait(2000);
            cy.then(() => {
                if (Date.now() < endTime) test();
            });
        };
        test();
    });
});

Simple static html site

<!DOCTYPE html>
<html lang="en">
<head>
</head>
<body>
	<input id="testinput">
</body>
</html>

Versions

Cypress 3.2.0 / 3.5.0 / 3.6.0 Windows 10

About this issue

Original URL
State: open
Created 5 years ago
Reactions: 23
Comments: 57 (9 by maintainers)

Most upvoted comments

Any update on memory leak

ronwongsk661 on Jan 29, 2021

same problem 9.6.1

import { links } from './links'; // 500 items

context('Full version tests', () => {
	beforeEach(() => {
		cy.login();
	});

	links.forEach(link => {
		it(`should load page ${link}`, () => {
			cy.visit(link); 
			cy.wait(5000);
			cy.hasNotErrorMessage();
		});
	});
});

JaLe29 on Jun 1, 2022

8.5.0 as well…

reuben-rodrigues on Sep 30, 2021

@Oliboy50 not really, i still have it in 6.0.0

andrei22b on Dec 17, 2020

@jennifer-shehane if you want another easily reproductible example => I guess I’m experiencing something similar in this project on cypress 4.10.0

it runs a single test which is pretty fast at the beginning and starts to be really slow after ~50 seconds of execution

I tried to use "numTestsKeptInMemory": 0 cypress configuration but it didn’t help at all 🤷

if you want to try it out, please install node v12.x and run the following commands:

git clone https://github.com/Oliboy50/coinche.git
cd coinche

cd client
npm install
cd ..

cd server
npm install
cd ..

cd e2e
npm install
npm run dev

Cypress GUI will pop up and you’ll be able to run the test I’m talking about

hope it will help (I’d love to have a faster test, one which does not make my computer burn ❤️)

Oliboy50 on Jul 18, 2020

Hi @nagash77 , I have created reproducible example of this issue: https://github.com/StefanTegeltija/memory-leak-in-long-running-single-test, sorry I haven’t used for of Cypres Test Tiny but it should not be hard to run my example. In order to run tests you just need to:

Download this repo
Run npm install
Run npm run run:dev You will probably see issue in every run 😃 Please let me know is you need anything else 😃 Chrome version: Version 120.0.6099.71 (Official Build) (x86_64)

StefanTegeltija on Jan 5, 2024

any updates ??

Error code: Out of Memory

CloneOfAlex on Jul 20, 2023

Check https://github.com/cypress-io/cypress/discussions/25557

I’v also added env var CYPRESS_NO_COMMAND_LOG=1 on our pipeline. Not much added value having the command log for remote runs.

I’ve added some memory graphs on twitter: https://twitter.com/op_kris/status/1636675020180058112?s=46&t=DPClh6K4rCQElpP_CUCryg showing the difference between the usage of the command log or not.

krisodb on Mar 21, 2023

Any updates on this from Cypress?

darkhillreturns on May 10, 2022

@Oliboy50 - Yea that looks good to me, for reference this is what we have in our plugins/index.js:

module.exports = (on, config) => {
    on('before:browser:launch', (browser = {}, launchOptions) => {
        if (browser.name === 'chrome') {
            launchOptions.args.push('--disable-web-security');
            launchOptions.args.push('--disable-site-isolation-trials');
            launchOptions.args.push('--max_old_space_size=1500');
            launchOptions.args.push('--disable-dev-shm-usage');
            return launchOptions;
        }
    });
}

You also may need to increase or decrease the max_old_space_size setting, 1500 worked for us but maybe you need more or less memory. I would try: 500, 1000, 2000, and 10000 and see if any of those work

If that does not work, I suggest trying out this logging package so you can see the exact error you are getting in the terminal when you run your pipeline: https://github.com/flotwig/cypress-log-to-output (for us, Cypress was swallowing the console errors)

You will need to use the "chromeWebSecurity": false, setting in your cypress/environments/cypress.{env}.json files, this logging package seems to make the browser ignore that flag for some reason

Note that we are on an older version of Cypress and older image, and we are running this on Gitlab CI: package.json: "cypress": "^4.12.1" .gitlab-ci.yml (image): name: cypress/included:4.9.0

pardamike on Nov 3, 2020

Closing this issue as duplicate because I’m very confident this is describing the same behavior as https://github.com/cypress-io/cypress/issues/4104

brian-mann on Jun 17, 2019