Answer interface for dynamic responses in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a JUnit test method that asserts two strings are equal.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.[1];

public class SampleTest {
    @Test
    void testStrings() {
        String expected = "hello";
        String actual = "hello";
        [1](expected, actual);
    }
}

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

AassertNull

BassertFalse

CassertTrue

DassertEquals

Attempts:

3 left

💡 Hint

Common Mistakes

Using assertTrue instead of assertEquals causes the test to check a boolean, not equality.

Using assertNull or assertFalse does not compare two strings.

The assertEquals method checks if two values are equal, which is what we want to test here.

2fill in blank

medium

Complete the code to create a dynamic test name using JUnit 5's @DisplayName annotation.

JUnit

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.DisplayName;

public class DynamicNameTest {
    @Test
    @DisplayName("Test for user: [1]")
    void testUser() {
        // test code here
    }
}

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

A"John"

BJohn

CuserName

D"userName"

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes causes a compilation error.

Using a variable name without quotes does not work in @DisplayName.

The @DisplayName annotation requires a string literal, so the user name must be in quotes.

3fill in blank

hard

Fix the error in the code to correctly implement a dynamic test with JUnit 5's @TestFactory.

JUnit

import org.junit.jupiter.api.DynamicTest;
import org.junit.jupiter.api.TestFactory;
import java.util.stream.Stream;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class DynamicTests {
    @TestFactory
    Stream<DynamicTest> dynamicTests() {
        return Stream.of(
            DynamicTest.dynamicTest("Test 1", () -> [1])
        );
    }
}

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

AassertTrue(1 > 2)

BassertEquals(2, 1 + 2)

CassertEquals(2, 1 + 1)

DassertNull(null)

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong expected values causes test failure.

Using assertions that do not compile or are invalid in lambda.

The lambda must contain a valid assertion. assertEquals(2, 1 + 1) correctly asserts that 1 + 1 equals 2.

4fill in blank

hard

Fill both blanks to create a parameterized test method that uses @ValueSource with integers.

JUnit

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

public class ParamTest {
    @ParameterizedTest
    @[2](ints = {1, 2, 3})
    void testNumbers(int number) {
        // test code
    }
}

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

AValueSource

BCsvSource

DMethodSource

Attempts:

3 left

💡 Hint

Common Mistakes

Using @CsvSource or @MethodSource without proper format causes errors.

Mismatching import and annotation names.

The @ValueSource annotation is used to provide primitive values like integers to parameterized tests.

5fill in blank

hard

Fill all three blanks to create a dynamic test stream that tests if strings are not empty.

JUnit

import org.junit.jupiter.api.DynamicTest;
import org.junit.jupiter.api.TestFactory;
import java.util.stream.Stream;
import static org.junit.jupiter.api.Assertions.assertTrue;

public class StringTests {
    @TestFactory
    Stream<DynamicTest> dynamicTestsForStrings() {
        String[] inputs = {"apple", "", "banana"};
        return Stream.of(inputs).map(input ->
            DynamicTest.dynamicTest("Test: " + input, () -> {
                [1].assertTrue(!input.[2](), "String is empty");
            })
        );
    }
}

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

Aorg.junit.jupiter.api.Assertions

BisEmpty

CassertTrue

Dlength

Attempts:

3 left

💡 Hint

Common Mistakes

Calling assertTrue without the Assertions class causes errors.

Using length() instead of isEmpty() changes the logic.

Mixing up assertTrue and assertFalse.

We use Assertions.assertTrue to check that the string is not empty by calling input.isEmpty().