Mocking & Virtualization interview questions — Medium
195 medium-level Mocking & Virtualization questions from our API Testing bank, each with the correct answer and an explanation of why it is correct.
What this covers
Mocking & Virtualization appears throughout API Testing interviews. At medium level, interviewers are typically checking that you have used it in practice: what you configured, what broke, and how you knew it worked. Work through these, then explain your answer out loud; the second part is what interviews actually test.
20 example questions
1. "Injecting failures to validate system resilience" — in Mocking, this describes which of the following?
- A. Proxying.
- B. Chaos testing.correct
- C. Stub mapping.
- D. Sandbox environment.
Why: chaos testing: Injecting failures to validate system resilience.
2. "Choosing among overlapping stubs by priority value" — in Mocking, this describes which of the following?
- A. Proxying.
- B. Fault injection.
- C. Priority matching.correct
- D. Stub mapping.
Why: priority matching: Choosing among overlapping stubs by priority value.
3. "WireMock rule matching a request to a canned response" — in Mocking, this describes which of the following?
- A. Response templating.
- B. Fault injection.
- C. Proxying.
- D. Stub mapping.correct
Why: stub mapping: WireMock rule matching a request to a canned response.
4. "Provider-hosted fake environment for third-party APIs" — in Mocking, this describes which of the following?
- A. Priority matching.
- B. Proxying.
- C. Sandbox environment.correct
- D. Stub mapping.
Why: sandbox environment: Provider-hosted fake environment for third-party APIs.
5. "Deliberately returning errors or malformed data to test resilience" — in Mocking, this describes which of the following?
- A. Fault injection.correct
- B. Response templating.
- C. Proxying.
- D. Priority matching.
Why: fault injection: Deliberately returning errors or malformed data to test resilience.
6. "Building dynamic mock responses from request data" — in Mocking, this describes which of the following?
- A. Priority matching.
- B. Chaos testing.
- C. Response templating.correct
- D. Fault injection.
Why: response templating: Building dynamic mock responses from request data.
7. Which of the following statements about Mocking is TRUE?
- A. WireMock can only return instant, successful 200 responses.
- B. Mocks and stubs are strictly identical concepts with no distinction.
- C. Simulating timeouts is impossible with mock servers.
- D. Service virtualization simulates dependent APIs so testing can proceed independently.correct
Why: Mocks decouple teams from unavailable or costly dependencies.
8. Identify the accurate statement about Mocking:
- A. Mocking eliminates the need for any integration testing forever.
- B. Mocks and stubs are strictly identical concepts with no distinction.
- C. Recorded stubs can never be edited after capture.
- D. Service virtualization simulates dependent APIs so testing can proceed independently.correct
Why: Mocks decouple teams from unavailable or costly dependencies.
9. Which statement correctly describes Mocking?
- A. Service virtualization simulates dependent APIs so testing can proceed independently.correct
- B. Mocks and stubs are strictly identical concepts with no distinction.
- C. Mocking eliminates the need for any integration testing forever.
- D. WireMock can only return instant, successful 200 responses.
Why: Mocks decouple teams from unavailable or costly dependencies.
10. "Forwarding unmatched requests to a real backend" — in Mocking, this describes which of the following?
- A. Chaos testing.
- B. Fault injection.
- C. Stub mapping.
- D. Proxying.correct
Why: proxying: Forwarding unmatched requests to a real backend.
11. In Mocking, which of the following is described as: "Choosing among overlapping stubs by priority value"?
- A. Proxying.
- B. Stub mapping.
- C. Sandbox environment.
- D. Priority matching.correct
Why: priority matching: Choosing among overlapping stubs by priority value.
12. In Mocking, which of the following is described as: "Injecting failures to validate system resilience"?
- A. Chaos testing.correct
- B. Fault injection.
- C. Priority matching.
- D. Sandbox environment.
Why: chaos testing: Injecting failures to validate system resilience.
13. In the context of Mocking, which of the following is a correct statement?
- A. Mocking eliminates the need for any integration testing forever.
- B. Simulating timeouts is impossible with mock servers.
- C. Service virtualization simulates dependent APIs so testing can proceed independently.correct
- D. Service virtualization requires all real dependencies to be online.
Why: Mocks decouple teams from unavailable or costly dependencies.
14. Which Mocking concept matches this description: "Deliberately returning errors or malformed data to test resilience"?
- A. Chaos testing.
- B. Fault injection.correct
- C. Response templating.
- D. Stub mapping.
Why: fault injection: Deliberately returning errors or malformed data to test resilience.
15. Which Mocking concept matches this description: "Injecting failures to validate system resilience"?
- A. Priority matching.
- B. Proxying.
- C. Response templating.
- D. Chaos testing.correct
Why: chaos testing: Injecting failures to validate system resilience.
16. Which Mocking concept matches this description: "Provider-hosted fake environment for third-party APIs"?
- A. Proxying.
- B. Sandbox environment.correct
- C. Stub mapping.
- D. Response templating.
Why: sandbox environment: Provider-hosted fake environment for third-party APIs.
17. In Mocking, which of the following is described as: "Building dynamic mock responses from request data"?
- A. Sandbox environment.
- B. Priority matching.
- C. Response templating.correct
- D. Fault injection.
Why: response templating: Building dynamic mock responses from request data.
18. In Mocking, which of the following is described as: "Provider-hosted fake environment for third-party APIs"?
- A. Response templating.
- B. Chaos testing.
- C. Fault injection.
- D. Sandbox environment.correct
Why: sandbox environment: Provider-hosted fake environment for third-party APIs.
19. In Mocking, which of the following is described as: "Deliberately returning errors or malformed data to test resilience"?
- A. Stub mapping.
- B. Sandbox environment.
- C. Fault injection.correct
- D. Proxying.
Why: fault injection: Deliberately returning errors or malformed data to test resilience.
20. In Mocking, which of the following is described as: "WireMock rule matching a request to a canned response"?
- A. Fault injection.
- B. Stub mapping.correct
- C. Sandbox environment.
- D. Proxying.
Why: stub mapping: WireMock rule matching a request to a canned response.