@ArgumentsSource with custom providers in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the correct JUnit annotation for parameterized tests.

JUnit

import org.junit.jupiter.params.provider.[1];

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ABeforeEach

BTest

CArgumentsSource

DDisplayName

Attempts:

3 left

💡 Hint

Common Mistakes

Importing @Test instead of @ArgumentsSource

Using annotations from JUnit 4 instead of JUnit Jupiter

The @ArgumentsSource annotation is imported from org.junit.jupiter.params.provider package to provide custom argument sources.

2fill in blank

medium

Complete the code to declare a parameterized test method using a custom ArgumentsProvider class named CustomProvider.

JUnit

@ParameterizedTest
@ArgumentsSource([1].class)
void testWithCustomProvider(String input) {
    // test code here
}

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ACustomProvider

BArgumentsSource

CTest

DValueSource

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the annotation name instead of the provider class

Omitting the .class suffix

The @ArgumentsSource annotation requires the class of the custom provider to supply arguments for the test method.

3fill in blank

hard

Fix the error in the custom ArgumentsProvider class by completing the method signature correctly.

JUnit

public class CustomProvider implements ArgumentsProvider {
    @Override
    public Stream<Arguments> [1](ExtensionContext context) {
        return Stream.of(Arguments.of("apple"), Arguments.of("banana"));
    }
}

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AgetArguments

BprovideArguments

Carguments

Dprovide

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method name like getArguments

Missing the ExtensionContext parameter

The method to override in ArgumentsProvider interface is provideArguments with ExtensionContext parameter.

4fill in blank

hard

Fill both blanks to create a parameterized test method that uses the custom provider and asserts the input is not null.

JUnit

@ParameterizedTest
@ArgumentsSource([1].class)
void testInputIsNotNull([2] input) {
    assertNotNull(input);
}

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ACustomProvider

BString

Cint

DArguments

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong parameter type like int

Using Arguments type instead of the actual argument type

The test uses CustomProvider as the argument source and the input parameter type is String to match provided arguments.

5fill in blank

hard

Fill all three blanks to implement a custom ArgumentsProvider that provides two integer arguments and use it in a parameterized test method.

JUnit

public class IntProvider implements ArgumentsProvider {
    @Override
    public Stream<Arguments> [1](ExtensionContext context) {
        return Stream.of(Arguments.of([2]), Arguments.of([3]));
    }
}

@ParameterizedTest
@ArgumentsSource(IntProvider.class)
void testWithInts(int number) {
    assertTrue(number > 0);
}

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AprovideArguments

B5

C10

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method name

Providing arguments of wrong type

Using variable names instead of values in Arguments.of()

The method provideArguments returns a stream of Arguments with integer values 5 and 10 to be used in the test method.