How would you perform boundary value testing for message length in the EPD Pilot?

• A. Test minimum, maximum, and just-below/above limits, including empty payloads and maximum allowed payloads.
• B. Only test with empty payload.
• C. Ignore length constraints.
• D. Test only the maximum length.

Answer: (C)

Boundary value testing focuses on how the system handles data right at the edges of what it should accept. For message length in the EPD Pilot, you explore the limits of the allowed length by checking several edge cases: an empty payload if the protocol allows it, the minimum valid length, values just inside the maximum limit, the maximum allowed length, and values just beyond that limit.

Why these matter: many bugs show up exactly at boundaries—length checks can have off-by-one errors, allocations can fail or overflow, and parsing logic might behave differently when a length crosses a boundary. Testing an empty payload confirms whether zero-length messages are allowed or properly rejected. Testing the minimum non-empty length ensures small messages are processed correctly. Testing just inside the maximum confirms near-capacity messages are handled without truncation or miscalculation. Testing the maximum verifies the true limit is supported. Testing just beyond the maximum checks that the system rejects or handles overflow safely.

Overall, this approach validates that length constraints are enforced consistently and securely. Ignoring constraints or testing only a single length misses these critical edge cases and can hide robustness or security issues.