@BeforeEach method in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run the setup method before each test.

JUnit

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

public class CalculatorTest {

    private Calculator calculator;

    @[1]
    void setup() {
        calculator = new Calculator();
    }

    @Test
    void testAddition() {
        int result = calculator.add(2, 3);
        assertEquals(5, result);
    }
}

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

AAfterEach

BBeforeAll

CTest

DBeforeEach

Attempts:

3 left

💡 Hint

Common Mistakes

Using @BeforeAll instead of @BeforeEach

Forgetting the @BeforeEach annotation

Using @Test annotation on setup method

The @BeforeEach annotation tells JUnit to run the setup method before each test method.

2fill in blank

medium

Complete the code to initialize the list before each test.

JUnit

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

public class ListTest {

    private List<String> items;

    @BeforeEach
    void init() {
        items = new [1]<>();
    }

    @Test
    void testListIsEmpty() {
        assertTrue(items.isEmpty());
    }
}

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AArrayList

BTreeSet

CHashSet

DLinkedList

Attempts:

3 left

💡 Hint

Common Mistakes

Using Set implementations instead of List

Not initializing the list before tests

Using LinkedList which is less common here

ArrayList is a common List implementation used to initialize the list before each test.

3fill in blank

hard

Fix the error in the setup method annotation.

JUnit

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

public class UserServiceTest {

    private UserService service;

    @[1]
    void setup() {
        service = new UserService();
    }

    @Test
    void testUserCreation() {
        assertNotNull(service);
    }
}

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ABeforeEach

BBeforeall

CBeforeEach()

DBeforeEachTest

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong casing like @Beforeall

Adding parentheses to annotation

Using non-existent annotations

The correct annotation is @BeforeEach without parentheses and with correct casing.

4fill in blank

hard

Fill both blanks to create a setup method that initializes count and flag before each test.

JUnit

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

public class CounterTest {

    private int count;
    private boolean flag;

    @[1]
    void setup() {
        count = 0;
        flag = [2];
    }

    @Test
    void testInitialValues() {
        assertEquals(0, count);
        assertFalse(flag);
    }
}

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ABeforeEach

Btrue

Cfalse

DBeforeAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using @BeforeAll instead of @BeforeEach

Setting flag to true instead of false

Forgetting the annotation

The setup method must be annotated with @BeforeEach and flag initialized to false before each test.

5fill in blank

hard

Fill all three blanks to create a setup method that initializes a map with a key and value before each test.

JUnit

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

public class MapTest {

    private Map<String, Integer> data;

    @[1]
    void setup() {
        data = new [2]<>();
        data.put("count", [3]);
    }

    @Test
    void testMapInitialization() {
        assertEquals(1, data.get("count"));
    }
}

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

ABeforeEach

BHashMap

C1

DTreeMap

Attempts:

3 left

💡 Hint

Common Mistakes

Using @BeforeAll instead of @BeforeEach

Using TreeMap instead of HashMap

Putting wrong value in the map

The setup method uses @BeforeEach, initializes data as a HashMap, and puts key "count" with value 1.