Swift Quality Control & Assurance 5

Question 1

What is the recommended way to test asynchronous Swift code using async/await in XCTest?

Accepted Answer

Mark the test function as async and use await directly

Answer

Swift 5.5+ XCTest supports async test functions natively — mark the test `async` and use `await` directly without needing XCTestExpectation.

Question 2

What is 'boundary value analysis' in software quality assurance for Swift apps?

Accepted Answer

Testing values at the edges of valid input ranges where bugs are most likely

Answer

Boundary value analysis focuses test inputs on the minimum, maximum, and just-outside-range values where off-by-one errors commonly occur.

Question 3

In a Swift CI/CD pipeline, what is the purpose of a 'gate' on test results?

Accepted Answer

To block merging or deploying code if tests fail

Answer

A quality gate blocks the pipeline from proceeding to merge or deploy if the test suite reports failures, enforcing code quality standards.

Question 4

Which Xcode instrument is best suited for detecting Swift memory leaks caused by retain cycles?

Accepted Answer

Leaks instrument

Answer

The Leaks instrument in Xcode Instruments specifically detects memory that has been allocated but can no longer be reached, including retain cycle leaks.

Question 5

What does 'XCTAssertNil' test for in a Swift unit test?

Accepted Answer

That a given expression evaluates to nil

Answer

XCTAssertNil fails the test if the provided expression is not nil, verifying that an optional is in its absent (nil) state.

Swift Practice Test

Swift Practice Test

Swift Quality Control & Assurance 5