Test result publishing in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to publish the test result using JUnit's assertion.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class CalculatorTest {
    @Test
    public void testAddition() {
        int result = 2 + 3;
        assertEquals([1], result);
    }
}

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

A7

B4

C5

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using the actual result as the expected value.

Mixing up the order of expected and actual in assertEquals.

The expected result of 2 + 3 is 5, so assertEquals(5, result) correctly publishes the test result.

2fill in blank

medium

Complete the code to publish a test failure when the condition is false.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class NumberTest {
    @Test
    public void testIsPositive() {
        int number = -1;
        assertTrue([1]);
    }
}

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

Anumber < 0

Bnumber > 0

Cnumber == 0

Dnumber >= 0

Attempts:

3 left

💡 Hint

Common Mistakes

Using a condition that is false for the given number.

Confusing greater than and less than operators.

The test expects the number to be positive, so number > 0 is the correct condition to assert true.

3fill in blank

hard

Fix the error in the test result publishing code by completing the assertion.

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class StringTest {
    @Test
    public void testStringLength() {
        String text = "hello";
        assertEquals([1], text.length());
    }
}

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

A5

B6

C4

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using the actual length as the expected value.

Off-by-one errors in counting string length.

The string "hello" has length 5, so the expected value in assertEquals should be 5.

4fill in blank

hard

Fill both blanks to publish test results for checking if a list contains a specific element.

JUnit

import org.junit.jupiter.api.Test;
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]([2]));
    }
}

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

Acontains

B"banana"

C"orange"

Dadd

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method that modifies the list instead of checking.

Checking for an element not in the list.

The contains method checks if the list has the element. Here, we check if "banana" is in the list, so fruits.contains("banana") is correct.

5fill in blank

hard

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

JUnit

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

public class MapTest {
    @Test
    public void testMapEntry() {
        Map<String, Integer> scores = Map.of("Alice", 90, "Bob", 85);
        assertEquals([1], scores.get([2]));
        assertTrue(scores.[3]([2]));
    }
}

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

A90

B"Alice"

CcontainsKey

D85

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up keys and values in the map.

Using a method that checks values instead of keys.

The test checks that the score for "Alice" is 90 and that the map contains the key "Alice". So, assertEquals(90, scores.get("Alice")) and assertTrue(scores.containsKey("Alice")) are correct.