Why advanced sources handle complex data in JUnit - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a basic JUnit test method.

JUnit

public class CalculatorTest {
    @Test
    public void testAddition() {
        Calculator calc = new Calculator();
        int result = calc.add(2, 3);
        assertEquals([1], result);
    }
}

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

A6

B7

C4

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong expected value in assertEquals.

Forgetting to import the @Test annotation.

The expected result of adding 2 and 3 is 5, so assertEquals(5, result) is correct.

2fill in blank

medium

Complete the code to assert that a list contains a specific element.

JUnit

import static org.junit.jupiter.api.Assertions.*;
import java.util.List;

public class ListTest {
    @Test
    public void testContainsElement() {
        List<String> fruits = List.of("apple", "banana", "cherry");
        assertTrue(fruits.[1]("banana"));
    }
}

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Aincludes

Bexists

Ccontains

Dhas

Attempts:

3 left

💡 Hint

Common Mistakes

Using methods that do not exist on List, like 'has' or 'exists'.

Confusing the method name with similar words.

The contains method checks if the list has the specified element.

3fill in blank

hard

Fix the error in the assertion to correctly compare two objects for equality.

JUnit

public class PersonTest {
    @Test
    public void testPersonEquality() {
        Person p1 = new Person("Alice", 30);
        Person p2 = new Person("Alice", 30);
        assert[1](p1, p2);
    }
}

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AEquals

BSame

CEqualTo

DEqualsObject

Attempts:

3 left

💡 Hint

Common Mistakes

Using assertSame instead of assertEquals for object equality.

Using non-existent assertion methods.

The correct JUnit assertion method to check object equality is assertEquals.

4fill in blank

hard

Fill both blanks to create a parameterized test method that runs with multiple inputs.

JUnit

import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;

public class NumberTest {
    @ParameterizedTest
    @ValueSource([1])
    public void testIsPositive(int number) {
        assertTrue(number [2] 0);
    }
}

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Aints = {1, 2, 3}

B{1, 2, 3}

C>

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the type attribute (e.g., ints =) in @ValueSource.

Using >= instead of >, which would accept zero as positive.

The @ValueSource annotation requires a type-specific attribute such as ints = {1, 2, 3} for integer values. The assertion uses > to verify the number is positive (greater than zero).

5fill in blank

hard

Fill all three blanks to write a test that verifies a map contains a key with a specific value.

JUnit

import static org.junit.jupiter.api.Assertions.*;
import java.util.Map;

public class MapTest {
    @Test
    public void testMapKeyValue() {
        Map<String, Integer> ages = Map.of("Bob", 25, "Carol", 30);
        assertTrue(ages.[1]("Bob") && ages.get("Bob") [2] [3]);
    }
}

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

AcontainsKey

B==

C25

Dequals

Attempts:

3 left

💡 Hint

Common Mistakes

Using '==' to compare Integer objects which may fail.

Using a method other than containsKey to check for keys.

The method containsKey checks if the map has the key. To compare the value, equals is used to compare with 25.