@NullSource and @EmptySource in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a null input test using @NullSource.

JUnit

@ParameterizedTest
@[1]
void testWithNullInput(String input) {
    assertNull(input);
}

Drag options to blanks, or click blank then click option'

ACsvSource

BEmptySource

CValueSource(strings = {""})

DNullSource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @EmptySource instead of @NullSource for null input.

Forgetting to annotate the test with @ParameterizedTest.

The @NullSource annotation provides a null value as input to the test method.

2fill in blank

medium

Complete the code to add an empty input test using @EmptySource.

JUnit

@ParameterizedTest
@[1]
void testWithEmptyInput(String input) {
    assertEquals("", input);
}

Drag options to blanks, or click blank then click option'

AEmptySource

BNullSource

CValueSource(strings = {"null"})

DCsvSource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @NullSource instead of @EmptySource for empty string input.

Not using @ParameterizedTest annotation.

The @EmptySource annotation provides an empty string as input to the test method.

3fill in blank

hard

Fix the error in the code to test both null and empty inputs using @NullSource and @EmptySource.

JUnit

@ParameterizedTest
@NullSource
@[1]
void testWithNullAndEmpty(String input) {
    assertTrue(input == null || input.isEmpty());
}

Drag options to blanks, or click blank then click option'

ACsvSource

BEmptySource

CNullSource

DValueSource(strings = {""})

Attempts:

3 left

💡 Hint

Common Mistakes

Using @ValueSource(strings = {""}) instead of @EmptySource.

Using @NullSource twice.

To test both null and empty inputs, use @NullSource and @EmptySource together.

4fill in blank

hard

Fill both blanks to create a parameterized test that checks null and empty inputs with proper annotations.

JUnit

@ParameterizedTest
@[1]
@[2]
void testNullAndEmptyInputs(String input) {
    assertTrue(input == null || input.isEmpty());
}

Drag options to blanks, or click blank then click option'

ANullSource

BEmptySource

CValueSource(strings = {""})

DCsvSource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @ValueSource instead of @EmptySource.

Missing one of the annotations.

Use @NullSource and @EmptySource together to test null and empty string inputs.

5fill in blank

hard

Fill all three blanks to create a parameterized test that uses @NullSource, @EmptySource, and a @ValueSource with strings.

JUnit

@ParameterizedTest
@[1]
@[2]
@[3](strings = {"test", "example"})
void testMultipleInputs(String input) {
    assertNotNull(input);
}

Drag options to blanks, or click blank then click option'

ANullSource

BEmptySource

CValueSource

DCsvSource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @CsvSource instead of @ValueSource for simple string inputs.

Forgetting to add @ParameterizedTest annotation (not shown here).

Combine @NullSource, @EmptySource, and @ValueSource to test null, empty, and specific string inputs.