ITPEC FE Morning October 2023 Question 46

Stub vs Driver in integration testing — stub replaces a low-level module in top-down testing.

In top-down integration testing, testing starts from the highest-level module and works downward. Lower-level modules that are not yet available are replaced by stubs — simple placeholders that return predefined responses.

• •Stub — substitutes a lower-level module (used in top-down testing)
• •Driver — substitutes a higher-level module that calls the module under test (used in bottom-up testing)

Why not others:
- (a) Driver — used in bottom-up testing, not top-down
- (b) Emulator — simulates an entire device or environment, not a module substitute
- (c) Simulator — models system behavior, not used as a module replacement in integration testing

Key rule: Top-down → Stub (fills in below). Bottom-up → Driver (calls from above).

AI-generated — may contain errors