Cypress Interview Questions & Answers (1970)

Cypress is an open-source JavaScript end-to-end testing framework that runs directly inside the browser. It's known for its time-travel debugger, automatic waiting, and developer-friendly API.

Selenium drives the browser from outside via WebDriver. Cypress runs inside the browser in the same event loop as your app — giving it native access to the DOM, network, and storage, but limiting it to a single browser tab and same-origin (until cy.origin()).

npm init -y
npm install --save-dev cypress
npx cypress open

• Test Runner (interactive GUI)
• Command API (cy.*)
• Fixtures folder
• Support & Plugins files
• cypress.config.ts
• Cypress Cloud (dashboard, parallelization, flake detection)

cy.get(selector) queries from the document root. cy.find(selector) is chained on an existing subject and queries only that subject's descendants:

cy.get('.cart').find('.item'); // items INSIDE the cart only

Most cy.* commands and every assertion re-run automatically until they pass or the command times out (default 4s). You almost never need cy.wait(ms).

Only for waiting on a specific network alias:

cy.intercept('POST', '/api/orders').as('createOrder');
cy.get('[data-test="submit"]').click();
cy.wait('@createOrder').its('response.statusCode').should('eq', 201);

Never use cy.wait(2000) — it's a flake magnet.

cy.get('.list li').first().should('contain', 'Apples').click();

Each command yields a subject to the next. Assertions retry the whole chain.

cy.get('[data-test="total"]').should('have.text', '$42.00');
cy.url().should('include', '/checkout');
cy.get('.error').should('not.exist');

cy.get('[data-test="email"]').type('qa@example.com');
cy.get('[data-test="pwd"]').type('secret{enter}');

// cypress.config.ts
export default defineConfig({
  e2e: { baseUrl: 'https://qa.example.com' },
});
// spec
cy.visit('/login');

Cypress auto-accepts them. To assert, stub the window method:

cy.on('window:confirm', (msg) => {
  expect(msg).to.eq('Delete order?');
  return true;
});

The modern network-stubbing API. Match by method + URL and either spy, stub, or delay:

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

Use cy.intercept. cy.route is deprecated since Cypress 6 and doesn't handle fetch/XHR uniformly.

// cypress/fixtures/users.json — { "id": 1, "email": "qa@x.com" }
cy.fixture('users').then((u) => {
  cy.intercept('GET', '/api/users/1', u);
});

cy.intercept('GET', '/api/slow', (req) => {
  req.reply({ delay: 3000, body: { ok: true } });
});

cy.wait('@createOrder').then(({ request, response }) => {
  expect(request.body).to.include({ items: 3 });
  expect(response.statusCode).to.eq(201);
});

// cypress/support/commands.js
Cypress.Commands.add('login', (email, pwd) => {
  cy.request('POST', '/api/login', { email, pwd })
    .then(({ body }) => window.localStorage.setItem('token', body.token));
});
// spec
cy.login('qa@x.com', 'secret');

Log in via cy.request() or cy.session() to skip the UI login flow on every test:

beforeEach(() => {
  cy.session('qa-user', () => {
    cy.request('POST', '/api/login', creds)
      .its('body.token').then((t) => localStorage.setItem('token', t));
  });
});

Running commands against a different origin (needed for third-party OAuth pages, Auth0, Okta, Google sign-in). Enable with experimentalOriginDependencies and wrap the cross-origin block.

Node-side extensions loaded in cypress.config.ts → setupNodeEvents. Used for DB seeding, file preprocessors, image diffing, coverage collection, and custom tasks (cy.task()).

cy.get('input[type="file"]').selectFile('cypress/fixtures/avatar.png');

Built-in — Cypress screenshots + videos every failing test by default. Configure via cypress.config.ts:

screenshotOnRunFailure: true,
video: true,

npx cypress run --browser chrome --headless
# specific spec
npx cypress run --spec cypress/e2e/login.cy.ts

Use Cypress Cloud: cypress run --record --parallel --key <key>. Free open-source alt: sorry-cypress (self-hosted).

- uses: cypress-io/github-action@v6
  with:
    browser: chrome
    record: true
    parallel: true
  env:
    CYPRESS_RECORD_KEY: ${{ secrets.CYPRESS_RECORD_KEY }}

• Single browser at a time (no true multi-tab/window)
• JavaScript/TypeScript only
• Limited iframe support without cy.origin
• No native mobile automation (use Appium)

Playwright wins for cross-browser, multi-tab, mobile emulation, parallel-by-default. Cypress wins for the interactive time-travel runner and the mature dashboard. See our Cypress vs Playwright comparison. Also related: Cypress for Freshers and Cypress at 5 YOE.