Fixing Test Flakiness, Element Visibility Issues, and Memory Leaks in Cypress

Details: Category: Troubleshooting Tips; By Mindful Chase; 13.Feb; Hits: 48

Developers using Cypress for end-to-end testing sometimes encounter issues where tests intermittently fail due to flakiness, element visibility errors prevent actions, or memory leaks slow down test execution. This problem, known as the 'Cypress Test Flakiness, Element Visibility Issues, and Memory Leaks,' occurs due to improper waiting strategies, DOM re-renders, and inefficient memory management.

Mindful Chase

Writing Code, Writing Stories

tbd

Experience

tbd

More to Explore

Understanding Test Flakiness, Element Visibility Issues, and Memory Leaks in Cypress

Cypress is a popular JavaScript-based testing framework, but unreliable test execution, dynamic UI updates, and excessive resource consumption can degrade test stability and performance.

Common Causes of Cypress Issues

Test Flakiness: Unstable network requests, inconsistent element timing, and race conditions.
Element Visibility Issues: Hidden elements, detached DOM nodes, and incorrect CSS selectors.
Memory Leaks: Excessive test retries, growing DOM snapshots, and unoptimized browser sessions.
Scalability Challenges: Long test execution times, inefficient parallelization, and browser memory consumption.

Diagnosing Cypress Issues

Debugging Test Flakiness

Check network requests:

cy.intercept('GET', '/api/data').as('getData');
cy.wait('@getData');

Ensure deterministic test execution:

cy.clock();
cy.tick(5000);

Retry failed assertions:

cy.get('.btn').should('be.visible');

Identifying Element Visibility Issues

Verify element visibility:

cy.get('.modal').should('be.visible');

Ensure element is not detached:

cy.get('.btn').should('exist');

Use force click for hidden elements:

cy.get('.btn').click({ force: true });

Detecting Memory Leaks

Monitor DOM snapshot growth:

cy.task('memoryUsage');

Check active browser sessions:

cy.exec('ps aux | grep chrome');

Reduce test retries to prevent excessive memory consumption:

retries: 2

Profiling Scalability Challenges

Measure test execution time:

cy.task('performanceMetrics');

Enable parallel execution:

cypress run --parallel

Check browser memory consumption:

cy.task('getHeapSnapshot');

Fixing Cypress Performance and Stability Issues

Fixing Test Flakiness

Use proper waiting strategies:

cy.wait('@getData', { timeout: 10000 });

Stub network requests:

cy.intercept('GET', '/api/data', { fixture: 'data.json' }).as('mockData');

Ensure element stability before interactions:

cy.get('.btn', { timeout: 5000 }).should('be.enabled');

Fixing Element Visibility Issues

Scroll elements into view:

cy.get('.btn').scrollIntoView();

Ensure animations complete before clicking:

cy.get('.modal', { timeout: 5000 }).should('have.class', 'open');

Use alternative selectors:

cy.get('[data-cy=submit]');

Fixing Memory Leaks

Limit the number of snapshots:

Cypress.config('numTestsKeptInMemory', 5);

Close browser sessions after tests:

cy.window().then(win => win.close());

Optimize test cleanup:

cy.clearCookies();
cy.clearLocalStorage();

Improving Scalability

Enable test sharding:

cypress run --record --parallel --group 'integration-tests'

Optimize test retries:

cypress.json:
"retries": { "runMode": 2, "openMode": 1 }

Use headless mode for CI runs:

cypress run --headless

Preventing Future Cypress Issues

Use consistent waiting strategies to avoid test flakiness.
Ensure element stability before interacting with UI components.
Monitor memory consumption and optimize test retries.
Enable parallel execution to scale test coverage efficiently.

Conclusion

Cypress issues arise from unstable test execution, hidden elements, and excessive memory usage. By refining waiting strategies, stabilizing UI interactions, and optimizing test performance, developers can ensure reliable and efficient Cypress testing.

FAQs

1. Why are my Cypress tests flaky?

Possible reasons include inconsistent network requests, element re-renders, and improper waiting strategies.

2. How do I fix Cypress element visibility issues?

Ensure elements are in view, wait for animations to complete, and use force clicks where necessary.

3. Why does Cypress consume high memory?

Potential causes include excessive test retries, large DOM snapshots, and unoptimized browser sessions.

4. How can I improve Cypress test execution time?

Use parallel execution, optimize test retries, and disable unnecessary snapshots.

5. How do I debug Cypress performance bottlenecks?

Monitor execution time, analyze heap snapshots, and optimize waiting strategies.

Contact Us