Web Development Testing 5

Question 1

What is 'snapshot testing' as used in Jest?

Accepted Answer

Serializing a component's rendered output and comparing it to a stored reference on future runs

Answer

Jest snapshot testing serializes a component's output (often JSX/HTML) into a `.snap` file and fails if the output changes unexpectedly.

Question 2

Which Playwright locator is most resistant to CSS/styling changes when targeting elements?

Accepted Answer

.getByRole('button', { name: 'Submit' })

Answer

Role-based locators use ARIA semantics rather than visual attributes, making them resilient to style changes and better for accessibility.

Question 3

What is the purpose of `afterAll` in Jest?

Accepted Answer

Runs a cleanup function once after all tests in the describe block complete

Answer

`afterAll` runs a teardown function exactly once after all tests in its scope have finished, useful for closing database connections or servers.

Question 4

In load testing, what does 'throughput' measure?

Accepted Answer

The number of requests processed per unit of time

Answer

Throughput measures how many requests (or transactions) a system can handle per second, indicating its processing capacity.

Question 5

What is the difference between a 'mock' and a 'stub' in testing terminology?

Accepted Answer

Mocks verify behavior (expectations); stubs provide canned responses without assertions

Answer

Stubs return pre-configured responses to make tests work, while mocks additionally assert that specific interactions occurred (they are pre-programmed with expectations).

Web Development Practice Test

Web Development Practice Test

Web Development Testing 5