expect() for BDD assertions in Cypress - Build an Automation Script

Verify the page title and button text using BDD expect assertions

Preconditions (2)

Step 1: Open the URL 'https://example.cypress.io'

Step 2: Check that the page title is exactly 'Cypress.io: Kitchen Sink'

Step 3: Locate the button with id 'query-btn'

Step 4: Verify that the button text contains the word 'Button'

✅ Expected Result: The page title matches exactly 'Cypress.io: Kitchen Sink' and the button with id 'query-btn' contains text with the word 'Button'

Automation Requirements - Cypress

Assertions Needed:

Assert page title equals 'Cypress.io: Kitchen Sink' using expect()

Assert button text contains 'Button' using expect()

Best Practices:

Use cy.visit() to open the page

Use cy.title() to get the page title

Use cy.get() with id selector '#query-btn' to locate the button

Use .should() with a callback and expect() for assertions

Avoid hardcoded waits; rely on Cypress automatic waits

Automated Solution

Cypress

describe('BDD expect() assertions example', () => {
  it('checks page title and button text', () => {
    cy.visit('https://example.cypress.io');

    cy.title().should('equal', 'Cypress.io: Kitchen Sink');

    cy.get('#query-btn').should('be.visible').then(($btn) => {
      expect($btn.text()).to.include('Button');
    });
  });
});

This test opens the Cypress example page using cy.visit(). Then it checks the page title with cy.title() and asserts it equals the expected string using .should('equal', ...). Next, it finds the button by its id #query-btn and ensures it is visible. Using .then(), it accesses the button's text and uses expect() to assert the text includes the word 'Button'. This approach uses Cypress best practices: automatic waiting, clear selectors, and BDD style assertions with expect().

Common Mistakes - 3 Pitfalls

Using cy.get() with an incorrect or overly complex selector

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

Using expect() outside of a .then() callback when working with Cypress commands

Bonus Challenge

Now add data-driven testing to check multiple buttons with different ids and expected text using expect() assertions

Show Hint

Practice

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

easy

A. To log messages in the console

B. To run the test suite faster

C. To select elements on the page

D. To check if the actual value matches the expected value

Solution

1. Step 1: Understand the role of expect()

   expect() is used to compare actual results with expected results in tests.

2. Step 2: Identify the correct purpose

   It helps verify if the app behaves as expected by checking values.

3. Final Answer:

   To check if the actual value matches the expected value -> Option D

4. Quick Check:

   expect() compares values [OK]

Hint: Remember: expect() checks actual vs expected values [OK]

Common Mistakes:

• Thinking expect() runs tests
• Confusing expect() with element selectors
• Using expect() to log messages

2. Which of the following is the correct syntax to assert that a variable count equals 5 using expect() in Cypress?

easy

A. expect(count).to.equal(5);

B. expect(count).toBe(5);

C. expect(count).equals(5);

D. expect(count).is(5);

Solution

1. Step 1: Recall Cypress BDD assertion syntax

   Cypress uses Chai assertions where to.equal() checks equality.

2. Step 2: Identify the correct syntax

   expect(count).to.equal(5); is the correct way to assert equality.

3. Final Answer:

   expect(count).to.equal(5); -> Option A

4. Quick Check:

   Use to.equal() for equality [OK]

Hint: Use to.equal() for equality checks in Cypress [OK]

Common Mistakes:

• Using toBe() which is Jest syntax
• Using equals() without to
• Using is() which is invalid

3. What will be the result of this Cypress assertion?

const title = 'Welcome';
expect(title).to.have.length(7);

medium

A. Test passes because 'Welcome' has 7 characters

B. Test fails because length is checked incorrectly

C. Syntax error due to wrong method

D. Test passes but length is 6

Solution

1. Step 1: Check the string length

   The string 'Welcome' has exactly 7 characters.

2. Step 2: Understand the assertion

   to.have.length(7) correctly asserts the string length is 7.

3. Final Answer:

   Test passes because 'Welcome' has 7 characters -> Option A

4. Quick Check:

   String length 7 matches assertion [OK]

Hint: Count characters to verify length assertions [OK]

Common Mistakes:

• Assuming length counts words, not characters
• Confusing length with array length
• Using wrong assertion method

4. Identify the error in this Cypress assertion:

expect(user.name).to.equals('Alice');

medium

A. Missing parentheses after user.name

B. Incorrect method name; should be to.equal

C. Should use expect(user).to.equal('Alice')

D. No error; assertion is correct

Solution

1. Step 1: Check the assertion method

   The correct Chai assertion method is to.equal, not to.equals.

2. Step 2: Confirm syntax correctness

   Using to.equals causes a runtime error because it is not defined.

3. Final Answer:

   Incorrect method name; should be to.equal -> Option B

4. Quick Check:

   Use to.equal, not to.equals [OK]

Hint: Remember: method is to.equal, not to.equals [OK]

Common Mistakes:

• Using to.equals instead of to.equal
• Confusing property access syntax
• Assuming expect needs parentheses after property

5. You want to check that an array items contains the string 'apple' using expect(). Which assertion correctly tests this?

hard

A. expect(items).to.equal('apple');

B. expect(items).to.have.length('apple');

C. expect(items).to.include('apple');

D. expect(items).to.contain.length('apple');

Solution

1. Step 1: Understand the goal

   You want to check if 'apple' is inside the array items.

2. Step 2: Choose the correct assertion

   to.include('apple') checks if the array contains that element.

3. Final Answer:

   expect(items).to.include('apple'); -> Option C

4. Quick Check:

   Use to.include() to check array contents [OK]

Hint: Use to.include() to check if array has an item [OK]

Common Mistakes:

• Using to.equal() which checks full equality
• Using length assertions incorrectly
• Combining contain and length wrongly