Best practices for selectors in Cypress - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select an element by its data attribute.

Cypress

cy.get('[[1]="submit-button"]')

Drag options to blanks, or click blank then click option'

Adata-cy

Bclass

Cid

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using id or class selectors which can break tests if UI changes.

Using generic attributes like name that are not stable.

Using data-cy attributes is a best practice for selectors in Cypress because it avoids brittle selectors tied to styling or layout.

2fill in blank

medium

Complete the code to select a button with an accessible role.

Cypress

cy.get('[1][name="login"]')

Drag options to blanks, or click blank then click option'

Abutton

Binput

Cspan

Ddiv

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting non-button elements that do not have button behavior.

Using generic selectors that are not specific to the element's role.

Using semantic HTML elements like button helps with accessibility and makes selectors clearer.

3fill in blank

hard

Fix the error in the selector to avoid using brittle class names.

Cypress

cy.get('.[1]-container')

Drag options to blanks, or click blank then click option'

Afooter

Bbtn-primary

Cheader

Dmain

Attempts:

3 left

💡 Hint

Common Mistakes

Using styling classes that change frequently.

Selecting elements that are not unique or meaningful.

Using semantic container names like main is more stable than styling classes like btn-primary.

4fill in blank

hard

Fill both blanks to create a selector that finds a list item with a specific test id and text content.

Cypress

cy.get('[[1]="item-3"]').contains('[2]')

Drag options to blanks, or click blank then click option'

Adata-test

BSubmit

CCancel

Ddata-cy

Attempts:

3 left

💡 Hint

Common Mistakes

Using generic attributes like data-test if the project standard is data-cy.

Selecting wrong text that does not match the element.

Using data-cy as a test attribute and contains with the visible text Submit ensures a robust selector.

5fill in blank

hard

Fill all three blanks to create a selector that finds an input by its test id and checks that it has a type attribute.

Cypress

cy.get('[[1]="email-input"]').should('[2]', '[3]')

Drag options to blanks, or click blank then click option'

Adata-cy

Bhave.attr

Cvisible

Dtype

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect attribute names or assertion methods.

Mixing up the order of assertion arguments.

This selector uses data-cy to find the input, then asserts it has the attribute type, ensuring the input is correct.

Practice

1. Which of the following is the best practice for choosing selectors in Cypress tests?

easy

A. Use text content that may change frequently.

B. Use CSS classes that might change with styling updates.

C. Use element positions like :nth-child() selectors.

D. Use unique IDs or custom data attributes for selectors.

Solution

1. Step 1: Understand selector stability

   Selectors should be stable and unique to avoid breaking tests when UI changes.

2. Step 2: Evaluate options for stability

   IDs and custom data attributes are stable and unique, unlike classes or text that can change.

3. Final Answer:

   Use unique IDs or custom data attributes for selectors. -> Option D

4. Quick Check:

   Stable selectors = IDs or data attributes [OK]

Hint: Pick selectors that rarely change, like IDs or data attributes [OK]

Common Mistakes:

• Using CSS classes that change with styling
• Selecting by visible text that may vary
• Relying on element order which can shift

2. Which of the following is the correct syntax to select an element with a custom attribute data-test='submit-btn' in Cypress?

easy

A. cy.get('[data-test=submit-btn]')

B. cy.get('data-test=submit-btn')

C. cy.get('#submit-btn')

D. cy.get('.submit-btn')

Solution

1. Step 1: Recall attribute selector syntax

   In CSS selectors, attributes are selected with square brackets and quotes if needed.

2. Step 2: Match correct Cypress syntax

   cy.get('[data-test=submit-btn]') correctly uses attribute selector syntax.

3. Final Answer:

   cy.get('[data-test=submit-btn]') -> Option A

4. Quick Check:

   Attribute selectors use brackets [] [OK]

Hint: Use brackets [] around attribute selectors in cy.get() [OK]

Common Mistakes:

• Omitting brackets for attribute selectors
• Using ID or class selectors incorrectly
• Missing quotes around attribute values

3. Given the HTML snippet:

<button data-cy='login-btn' class='btn primary'>Login</button>

What will cy.get('.btn.primary').click() do if the class changes to btn secondary later?

medium

A. The test will fail because the selector no longer matches.

B. The test will still pass because class selectors are stable.

C. The test will click a different button automatically.

D. The test will ignore the class and find the button by text.

Solution

1. Step 1: Understand selector dependency on class names

   The selector '.btn.primary' depends on the button having both classes 'btn' and 'primary'.

2. Step 2: Analyze effect of class change

   If the class changes to 'btn secondary', the selector '.btn.primary' no longer matches, causing failure.

3. Final Answer:

   The test will fail because the selector no longer matches. -> Option A

4. Quick Check:

   Class selectors break if classes change [OK]

Hint: Avoid class selectors that can change with styling [OK]

Common Mistakes:

• Assuming class selectors are stable
• Expecting automatic fallback to other selectors
• Thinking text selectors are used automatically

4. You wrote this Cypress selector: cy.get('button.submit-btn') but the test fails because the button has no class submit-btn. How can you fix it following best practices?

medium

A. Add the class submit-btn to the button in HTML.

B. Change selector to use a stable attribute like data-cy='submit-btn'.

C. Use cy.get('button') to select all buttons.

D. Use cy.contains('Submit') to select by text.

Solution

1. Step 1: Identify the problem with class selector

   The button lacks the class 'submit-btn', so the selector fails.

2. Step 2: Apply best practice for stable selectors

   Using a custom attribute like data-cy='submit-btn' is stable and recommended.

3. Final Answer:

   Change selector to use a stable attribute like data-cy='submit-btn'. -> Option B

4. Quick Check:

   Stable selectors use custom attributes [OK]

Hint: Use custom data attributes for stable selectors [OK]

Common Mistakes:

• Relying on missing or changing classes
• Selecting too broadly causing flaky tests
• Using text selectors that may change

5. You want to write a Cypress test that clicks the 'Save' button inside a form. The button has no ID but has data-test='save-btn'. The form has multiple buttons with different data-test attributes. Which selector is best to ensure you click the correct button inside the form?

hard

A. cy.get('form button').eq(0).click()

B. cy.get('[data-test=save-btn]').click()

C. cy.get('form').find('[data-test=save-btn]').click()

D. cy.get('button').contains('Save').click()

Solution

1. Step 1: Understand the need for context-specific selection

   Since multiple buttons have data-test attributes, selecting within the form narrows scope.

2. Step 2: Choose selector that scopes to form and targets correct button

   Using cy.get('form').find('[data-test=save-btn]') ensures the button inside the form is selected.

3. Final Answer:

   cy.get('form').find('[data-test=save-btn]').click() -> Option C

4. Quick Check:

   Scoped selectors avoid ambiguity [OK]

Hint: Scope selectors inside containers to avoid ambiguity [OK]

Common Mistakes:

• Selecting buttons globally causing wrong clicks
• Using text selectors that may match multiple elements
• Using index-based selectors that can break easily