Mutation testing concept (PIT) in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is mutation testing?

Mutation testing is a way to check how good your tests are by making small changes (mutations) to your code and seeing if the tests catch those changes.

beginner

What does PIT stand for in mutation testing?

PIT stands for "PIT" or "Pitest", a popular mutation testing tool for Java that works well with JUnit tests.

intermediate

How does PIT help improve test quality?

PIT changes parts of your code and runs tests to see if tests fail. If tests don't fail, it means tests might miss bugs, so you can improve them.

beginner

What is a 'mutant' in mutation testing?

A mutant is a version of your code with a small change introduced by the mutation testing tool to check if tests detect it.

intermediate

What does it mean if a mutant survives in PIT testing?

If a mutant survives, it means the tests did not catch the change, showing a possible weakness in your test coverage.

What is the main goal of mutation testing?

A To check if tests can find small code changes

B To speed up test execution

C To write new features automatically

D To remove bugs from production code

Mutation testing checks if your tests can detect small changes (mutations) in the code.

In PIT, what is a 'mutant'?

A A test case

B A bug report

C A changed version of the code

D A test runner

A mutant is a version of your code with a small change introduced to test your tests.

If a mutant survives, what does it mean?

A Tests caught the change

B Tests ran faster

C Code is error-free

D Tests missed the change

A surviving mutant means tests did not detect the change, indicating weak test coverage.

Which tool is commonly used for mutation testing in Java with JUnit?

A PIT

B JUnit5

C Selenium

D Mockito

PIT is a popular mutation testing tool for Java that works with JUnit.

What should you do if mutation testing shows many surviving mutants?

A Ignore them

B Write better tests to catch those mutants

C Delete the code

D Run tests less often

Surviving mutants mean tests miss bugs, so improving tests is needed.

Explain how mutation testing with PIT helps improve your test suite.

Think about how changing code and checking tests can show test quality.

Describe what a 'mutant' is and what it means when it survives mutation testing.

Focus on the mutant concept and test detection.