@ValueSource for simple values in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

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

@ValueSource is used to provide a set of simple values to a parameterized test method. It helps run the same test multiple times with different inputs.

beginner

Which types of simple values can @ValueSource provide in JUnit?

@ValueSource supports primitive types like int, long, double, short, byte, char, boolean, and also String arrays.

beginner

How do you write a parameterized test method using @ValueSource for integers 1, 2, and 3?

  @ParameterizedTest
  @ValueSource(ints = {1, 2, 3})
  void testWithInts(int number) {
    // test code using 'number'
  }

intermediate

What happens if you pass an unsupported type to @ValueSource?

JUnit will fail to run the test and throw an error because @ValueSource only supports specific simple types. You must use supported types only.

intermediate

Can @ValueSource be combined with other sources like @CsvSource in JUnit?

No, @ValueSource cannot be combined with other sources on the same test method. Use only one source annotation per parameterized test method.

Which of these is a valid use of @ValueSource in JUnit?

A @ValueSource(strings = {"apple", "banana"})

B @ValueSource(objects = {new Object(), new Object()})

C @ValueSource(lists = {{1,2}, {3,4}})

D @ValueSource(dates = {"2023-01-01"})

@ValueSource supports simple types like strings, but not objects, lists, or dates.

What annotation must be used together with @ValueSource to run parameterized tests?

A @ParameterizedTest

B @Test

C @BeforeEach

D @RepeatedTest

@ParameterizedTest tells JUnit to run the test multiple times with different parameters.

Which of these types is NOT supported by @ValueSource?

A int

B String

C boolean

D List<String>

@ValueSource supports primitive types and strings, but not collections like List.

How many source annotations can you use on a single parameterized test method?

A Three

B Two

C One

D Unlimited

Only one source annotation like @ValueSource or @CsvSource can be used per test method.

What will happen if you pass unsupported types to @ValueSource?

A Test runs normally

B JUnit throws an error

C Values are ignored

D Test is skipped

JUnit throws an error because @ValueSource only supports specific simple types.

Explain how to use @ValueSource to run a test multiple times with different simple values.

Think about how to feed different inputs to the same test method.

List the simple value types supported by @ValueSource in JUnit.

Focus on primitive types and strings.