@ParameterizedTest annotation in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @ParameterizedTest annotation in JUnit?

It allows running the same test method multiple times with different inputs, making tests more efficient and reducing code duplication.

beginner

How do you supply different input values to a @ParameterizedTest?

You use source annotations like @ValueSource, @CsvSource, or @MethodSource to provide the test data.

intermediate

What happens if a @ParameterizedTest fails for one input value?

Only the test run for that specific input fails; other inputs are tested independently, so you get detailed feedback on which inputs passed or failed.

beginner

Can @ParameterizedTest methods have parameters? If yes, how are they used?

Yes, the method parameters receive the input values from the source annotations for each test run.

beginner

Name two source annotations commonly used with @ParameterizedTest.

@ValueSource for simple values like ints or strings, and @CsvSource for multiple comma-separated values.

What does the @ParameterizedTest annotation do in JUnit?

A Runs a test multiple times with different inputs

B Marks a test to be ignored

C Runs a test only once

D Groups multiple tests together

@ParameterizedTest runs the same test method multiple times with different input values.

Which annotation is used to provide a list of simple values to a @ParameterizedTest?

A @CsvSource

B @Test

C @ValueSource

D @BeforeEach

@ValueSource supplies simple values like ints or strings to parameterized tests.

How do you provide multiple parameters per test run in a @ParameterizedTest?

A Using <code>@CsvSource</code>

B Using <code>@ValueSource</code>

C Using <code>@Test</code>

D Using <code>@BeforeAll</code>

@CsvSource allows multiple comma-separated values per test run.

If a @ParameterizedTest method has parameters, where do these values come from?

A From the test method itself

B From the source annotations like <code>@ValueSource</code>

C From the class constructor

D From the test report

The parameters are injected from the source annotations that provide test data.

What is the result if one input value causes a @ParameterizedTest to fail?

A The test passes anyway

B All test runs fail

C The test is skipped

D Only the run with that input fails

Only the test run with the failing input fails; others run independently.

Explain how @ParameterizedTest helps improve test code and give an example of a source annotation you can use.

Think about running one test method with many inputs.

Describe how you write a @ParameterizedTest method that tests if numbers are even using @ValueSource.

Imagine testing multiple numbers in one test method.