IPA FE Subject A 2024 Question 11
A question IPA Japan published in 令和６年度 基本情報技術者試験 科目A 公開問題 問11, translated into English. ITPEC is based on the same exams.
Same question on ITPEC: Oct 2023 Q46 +1 more
The integration test for software composed of modules arranged in a hierarchical structure is performed from a high-level module. In such a case, which of the following is a test module that is used as a substitute for a low-level module?
Explanation
Stub — in top-down integration testing, a stub stands in for a lower-level module that is not yet available.
Top-down integration starts from the highest-level module. The modules it calls may not be written or tested yet, so each one is replaced by a stub: a simple dummy module that accepts the call and returns a fixed or minimal result. As real lower modules are finished, they replace the stubs one by one.
The opposite approach, bottom-up integration, starts from low-level modules and needs a driver, a dummy higher-level module that calls the module under test and passes it test data.
Answer (d)
Why not others:
- •(a) Driver — substitutes an upper, calling module; it is used in bottom-up testing
- •(b) Emulator — imitates a whole hardware or software environment so programs can run on another platform; it is not a module substitute
- •(c) Simulator — models the behaviour of a system or device for experiments or training, not a placeholder for one module
Key rule: Stubs are called (they replace the level below); drivers call (they replace the level above).
System Development Technology · AI-written, may contain errors
This question comes from the past questions IPA Japan publishes, translated into English by ITPEC Practice. ITPEC Practice is an independent study tool and is not affiliated with IPA or ITPEC. See the original paper (PDF) or Report an issue.