Software Testing Case Studies & Practical Application 4

Question 1

A team inherits a legacy codebase with no tests. They want to add tests safely without inadvertently altering behavior. What is the recommended first step?

Accepted Answer

Write characterization tests to document current behavior before refactoring

Answer

Characterization tests capture the existing (possibly buggy) behavior of legacy code so that refactoring can proceed without inadvertently changing that behavior.

Question 2

A QA team must test a black-box system that accepts a numeric rating from 1 to 5. Using equivalence partitioning, which set of test values is most efficient?

Accepted Answer

0, 3, 6

Answer

Equivalence partitioning divides inputs into valid (1–5) and invalid (<1, >5) partitions; one representative from each—such as 0, 3, and 6—covers all partitions efficiently.

Question 3

An automated test suite takes 4 hours to run and blocks the CI pipeline. The fastest way to reduce feedback time while maintaining coverage is:

Accepted Answer

Parallelize test execution across multiple agents

Answer

Parallelizing test execution distributes the workload across multiple machines or agents, reducing total wall-clock time while maintaining the same coverage.

Question 4

A financial application crashes with a stack overflow error only after running for 72 hours in production. Which testing approach is designed to detect this class of defect?

Accepted Answer

Soak (endurance) testing

Answer

Soak testing runs the system under normal load for an extended period to uncover memory leaks, resource exhaustion, and other degradation issues that only appear over time.

Question 5

A tester changes a condition in the source code from '>' to '>=' and reruns the test suite. All tests still pass. What does this indicate?

Accepted Answer

The test suite has insufficient mutation coverage for this condition

Answer

In mutation testing, a surviving mutant (one not killed by the test suite) indicates the tests do not adequately cover or assert the behavior affected by that specific code change.

Software Testing Practice Test

Software Testing Practice Test

Software Testing Case Studies & Practical Application 4