expect() for BDD assertions in Cypress - Test Execution Trace

Test Overview

This test checks if a button with the ID submit-btn is visible and enabled on the page using Cypress expect() BDD assertions.

Test Code - Cypress

Cypress

describe('Button visibility and state test', () => {
  it('should verify the submit button is visible and enabled', () => {
    cy.visit('https://example.com')
    cy.get('#submit-btn').then(($btn) => {
      expect($btn).to.be.visible
      expect($btn).to.be.enabled
    })
  })
})

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Test runner initialized, no browser opened yet	—	PASS
2	Browser opens and navigates to 'https://example.com'	Browser shows the homepage of example.com	—	PASS
3	Find element with selector '#submit-btn' using cy.get	Button with ID 'submit-btn' is present in the DOM	Element found successfully	PASS
4	Use expect() to check if the button is visible	Button is visible on the page	expect($btn).to.be.visible	PASS
5	Use expect() to check if the button is enabled	Button is enabled and clickable	expect($btn).to.be.enabled	PASS
6	Test ends successfully	All assertions passed, test complete	—	PASS

Failure Scenario

Failing Condition: The button with ID 'submit-btn' is either not visible or disabled

Execution Trace Quiz - 3 Questions

What does the step 'cy.get('#submit-btn')' do in the test?

A Clicks the button with ID 'submit-btn'

B Finds the button element with ID 'submit-btn' on the page

C Checks if the button is visible

D Navigates to the submit page

Key Result

Using <code>expect()</code> with Cypress allows clear, readable checks of element states like visibility and enabled status, making tests easy to understand and maintain.

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