cy.session() for session caching in Cypress - Build an Automation Script

Automate login with session caching using cy.session()

Preconditions (3)

Step 1: Visit the login page at '/login'

Step 2: Enter 'testuser' in the username input field with id 'username'

Step 3: Enter 'Test@1234' in the password input field with id 'password'

Step 4: Click the login button with id 'loginBtn'

Step 5: Verify that the URL changes to '/dashboard'

Step 6: Log out by clicking the logout button with id 'logoutBtn'

Step 7: Visit the login page again at '/login'

Step 8: Use cy.session() to restore the previous login session

Step 9: Visit '/dashboard' directly and verify the user is still logged in

✅ Expected Result: The user logs in successfully once, the session is cached, and subsequent visits restore the session without requiring login again. The URL after login is '/dashboard'. After logout, the session is cleared and login is required again.

Automation Requirements - Cypress

Assertions Needed:

Verify URL is '/dashboard' after login

Verify session is cached and reused on subsequent visits

Verify user is logged out after clicking logout

Verify login page is shown after logout

Best Practices:

Use cy.session() to cache login session

Use selectors by id for stability

Use explicit assertions for URL and element visibility

Avoid hardcoded waits; use Cypress automatic waits

Structure test with beforeEach to handle session setup

Automated Solution

Cypress

describe('Login with session caching using cy.session()', () => {
  const username = 'testuser';
  const password = 'Test@1234';

  function login() {
    cy.visit('/login');
    cy.get('#username').type(username);
    cy.get('#password').type(password);
    cy.get('#loginBtn').click();
    cy.url().should('include', '/dashboard');
  }

  beforeEach(() => {
    cy.session('user-session', login);
  });

  it('should login and cache session', () => {
    // Session is created in beforeEach
    cy.visit('/dashboard');
    cy.url().should('include', '/dashboard');
    cy.get('#logoutBtn').should('be.visible');
  });

  it('should logout and require login again', () => {
    cy.visit('/dashboard');
    cy.get('#logoutBtn').click();
    cy.url().should('include', '/login');
    // After logout, session should be cleared
    cy.session('user-session', login, { cacheAcrossSpecs: false });
  });
});

The test suite uses cy.session() to cache the login session under the name 'user-session'.

The login function performs the login steps: visiting the login page, entering credentials, clicking login, and verifying the dashboard URL.

In beforeEach, cy.session() runs the login function only if the session is not cached, speeding up tests by reusing the session.

The first test verifies that after session caching, visiting '/dashboard' shows the dashboard page and logout button.

The second test logs out by clicking the logout button, verifies the URL returns to '/login', and clears the session cache to ensure login is required again.

Selectors use stable IDs, and assertions check URL and element visibility to confirm correct behavior.

Common Mistakes - 4 Pitfalls

Not using cy.session() and logging in before every test

Using unstable selectors like CSS classes that change often

Using cy.wait() with fixed time instead of relying on automatic waits

Not clearing session after logout

Bonus Challenge

Now add data-driven testing with 3 different sets of valid user credentials using cy.session()

Show Hint

Practice

1. What is the main purpose of using cy.session() in Cypress tests?

easy

A. To run tests in parallel

B. To clear cookies before each test

C. To cache user sessions and avoid repeated login steps

D. To generate random test data

Solution

1. Step 1: Understand what cy.session() does

   cy.session() caches login or setup steps so tests don't repeat them.

2. Step 2: Identify the main benefit

   This caching speeds up tests by reusing sessions instead of logging in every time.

3. Final Answer:

   To cache user sessions and avoid repeated login steps -> Option C

4. Quick Check:

   Session caching = Avoid repeated logins [OK]

Hint: Remember: cy.session() saves login to speed tests [OK]

Common Mistakes:

• Thinking it clears cookies instead of caching sessions
• Confusing it with parallel test execution
• Assuming it generates test data

2. Which of the following is the correct syntax to create a session with cy.session()?

easy

A. cy.session('user', () => { cy.login() })

B. cy.session('user', cy.login())

C. cy.session('user', function cy.login())

D. cy.session('user', cy.login)

Solution

1. Step 1: Recall cy.session() syntax

   The second argument must be a callback function that runs login steps, e.g., () => { cy.login() }.

2. Step 2: Check each option

   Only cy.session('user', () => { cy.login() }) correctly passes a callback function. The other options pass a function reference incorrectly, execute the function immediately, or use invalid syntax.

3. Final Answer:

   cy.session('user', () => { cy.login() }) -> Option A

4. Quick Check:

   Callback function syntax = cy.session('user', () => { cy.login() }) [OK]

Hint: Use arrow function for session callback: () => { ... } [OK]

Common Mistakes:

• Passing function call instead of function
• Using invalid function syntax
• Omitting the callback wrapper

3. Given the code below, what will be the output in the test run?

cy.session('admin', () => {
  cy.visit('/login')
  cy.get('#username').type('admin')
  cy.get('#password').type('password')
  cy.get('button[type=submit]').click()
})

cy.session('admin', () => {
  cy.visit('/dashboard')
})

medium

A. The login steps run only once; second session reuses cached login

B. Both sessions run login steps twice

C. Second session throws an error because visit is different

D. The test fails due to duplicate session keys

Solution

1. Step 1: Understand session caching behavior

   Sessions with the same key ('admin') cache the first login steps and reuse them in subsequent calls.

2. Step 2: Analyze the second cy.session() call

   The second call with the same key skips login steps and reuses the cached session, so only the visit to '/dashboard' runs.

3. Final Answer:

   The login steps run only once; second session reuses cached login -> Option A

4. Quick Check:

   Same key session = cached login reused [OK]

Hint: Same session key means login runs once only [OK]

Common Mistakes:

• Assuming login runs every time
• Thinking different visits cause errors
• Believing duplicate keys cause test failure

4. Identify the error in the following code using cy.session():

cy.session('user', () => {
  cy.visit('/login')
  cy.get('#user').type('test')
  cy.get('#pass').type('1234')
  cy.get('button').click()
})

cy.session('user', () => {
  cy.visit('/profile')
})

medium

A. The session key 'user' is reused, causing session cache conflict

B. The login callback does not return a promise or chain commands

C. The second session callback should include login steps again

D. No error; code works as expected

Solution

1. Step 1: Check session key usage

   Reusing the same session key 'user' is correct to cache and reuse the session.

2. Step 2: Verify callback structure

   The callback contains Cypress commands chained properly; no need to return a promise explicitly.

3. Step 3: Confirm second session usage

   The second session call reuses the cached session and visits '/profile' without error.

4. Final Answer:

   No error; code works as expected -> Option D

5. Quick Check:

   Reusing session key with proper callback = No error [OK]

Hint: Reusing session key with proper callback is valid [OK]

Common Mistakes:

• Thinking session keys must be unique per call
• Expecting explicit promise return in callback
• Assuming login steps must repeat every time

5. You want to speed up tests by caching sessions but notice some tests fail intermittently due to stale session data. How can you modify cy.session() usage to fix this?

hard

A. Use a different session key for every test to avoid caching

B. Add a validate callback to check session validity before reuse

C. Remove cy.session() and login every time

D. Clear cookies manually before each test instead of using cy.session()

Solution

1. Step 1: Understand stale session problem

   Stale sessions cause intermittent failures because cached data may expire or become invalid.

2. Step 2: Use validate callback in cy.session()

   The validate callback runs before reusing a session to confirm it is still valid, forcing a fresh login if needed.

3. Step 3: Avoid other options

   Using different keys disables caching, removing benefits. Removing cy.session() slows tests. Clearing cookies manually is less efficient.

4. Final Answer:

   Add a validate callback to check session validity before reuse -> Option B

5. Quick Check:

   Validate callback fixes stale session issues [OK]

Hint: Use validate callback to confirm session freshness [OK]

Common Mistakes:

• Disabling caching by changing keys unnecessarily
• Ignoring session validation causing flaky tests
• Removing session caching and slowing tests