Full-Stack Development Quality Control & Assurance 2 — Questions and Answers
Question 1: Which testing technique executes code without examining internal structure, focusing solely on inputs and outputs?
- White-box testing
- Black-box testing (Correct answer)
- Gray-box testing
- Static testing
Correct answer: Black-box testing
Black-box testing treats the system as an opaque box and validates behavior purely based on inputs and expected outputs.
Question 2: In a CI/CD pipeline, at which stage should unit tests typically run?
- After deployment to staging
- Only on the main branch
- On every commit, before integration tests (Correct answer)
- Before code is committed
Correct answer: On every commit, before integration tests
Unit tests run on every commit as the first gate in CI to catch failures early before slower integration tests execute.
Question 3: What does 'test coverage' primarily measure?
- Number of bugs found per test
- Percentage of code executed by tests (Correct answer)
- Time taken to run the test suite
- Number of test cases written
Correct answer: Percentage of code executed by tests
Test coverage measures the percentage of source code lines, branches, or paths that are exercised during test execution.
Question 4: Which type of testing verifies that a new code change has not broken existing functionality?
- Smoke testing
- Regression testing (Correct answer)
- Sanity testing
- Exploratory testing
Correct answer: Regression testing
Regression testing re-runs existing tests after changes to ensure previously working features still function correctly.
Question 5: What is a 'test double' in software testing?
- Running the same test twice for reliability
- A generic term for objects that replace real dependencies in tests (Correct answer)
- A second developer who reviews test code
- A production replica environment
Correct answer: A generic term for objects that replace real dependencies in tests
Test doubles (mocks, stubs, fakes, spies) are stand-ins for real dependencies that allow isolated unit testing.
Question 6: Which HTTP status code range indicates a server-side error that end-to-end tests should detect?
- 2xx
- 3xx
- 4xx
- 5xx (Correct answer)
Correct answer: 5xx
5xx status codes indicate server-side errors (e.g., 500 Internal Server Error) that signal broken backend logic.
Question 7: What is the primary purpose of a 'staging environment' in the QA process?
- To run load tests only
- To provide a production-like environment for final validation before release (Correct answer)
- To store test artifacts and logs
- To host the CI runner agents
Correct answer: To provide a production-like environment for final validation before release
Staging mirrors production configuration so QA teams can validate the full release candidate under realistic conditions.
Full-Stack Development Quality Control & Assurance 2
Which testing technique executes code without examining internal structure, focusing solely on inputs and outputs?