JSON fixture files in Cypress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this Cypress test using a JSON fixture?

Given the fixture file user.json contains {"name": "Alice", "age": 30}, what will be logged by this test?

Cypress

cy.fixture('user.json').then((user) => {
  cy.log(`Name: ${user.name}, Age: ${user.age}`)
})

A Name: Alice, Age: 30

B Name: undefined, Age: undefined

C Name: user.name, Age: user.age

D SyntaxError: Unexpected token

💡 Hint

Remember that cy.fixture loads the JSON content and passes it as an object.

The fixture file is loaded and parsed as an object. The user parameter contains the JSON data, so accessing user.name and user.age returns the correct values.

❓ assertion

intermediate

Which assertion correctly verifies the loaded JSON fixture data?

Assuming user.json contains {"name": "Bob", "active": true}, which assertion correctly checks that the user is active?

Cypress

cy.fixture('user.json').then((user) => {
  // Assertion here
})

A expect(user.active).to.be('true')

B expect(user.active).to.equal('true')

C expect(user.active).to.be.false

D expect(user.active).to.be.true

💡 Hint

Check the data type of the active property in the JSON.

The active property is a boolean true, so the assertion should check for boolean true, not string 'true'.

🔧 Debug

advanced

Why does this Cypress test fail to load the fixture?

The test code is:

cy.fixture('data.json').then((data) => {
  expect(data.items.length).to.equal(3)
})

The fixture file data.json exists but the test fails with TypeError: Cannot read property 'length' of undefined. What is the most likely cause?

A The fixture file name is misspelled in the test code.

B The JSON file does not have an <code>items</code> property at the root level.

C The <code>then</code> callback is missing a parameter.

D The test is missing <code>cy.visit()</code> before loading the fixture.

💡 Hint

Check the structure of the JSON file and the property being accessed.

The error means data.items is undefined, so the JSON does not contain an items property at the root. The test tries to access length of undefined, causing the error.

❓ framework

advanced

How does Cypress handle fixture file caching during tests?

Which statement best describes Cypress's behavior with fixture files when running multiple tests?

A Cypress reloads the fixture file from disk every time <code>cy.fixture()</code> is called.

B Cypress requires manual cache clearing to reload fixture files between tests.

C Cypress caches fixture files after the first load to improve performance in subsequent tests.

D Cypress does not support caching fixture files and always fetches them from the server.

💡 Hint

Think about how test runners optimize repeated file access.

Cypress caches fixture files after the first load to speed up tests by avoiding repeated disk reads.

🧠 Conceptual

expert

What is the best practice for managing large JSON fixture files in Cypress tests?

You have a large JSON fixture file with thousands of entries. Which approach is best to keep tests fast and maintainable?

A Split the large JSON into smaller fixture files and load only needed parts in each test.

B Load the entire large JSON fixture in every test to ensure consistency.

C Convert the JSON fixture into a JavaScript file and import it directly in tests.

D Avoid using fixtures and hardcode test data inside each test instead.

💡 Hint

Think about test speed and data relevance.

Splitting large fixtures into smaller files and loading only necessary data reduces memory use and speeds up tests.