4 / 17 : Junit-test life cycle

1. Lifecycle per-method. (default)

2. Lifecycle per-class.

Lifecycle per-method mode

• 테스트가 진행될때 메서드 단위로 새로운 인스턴스 생성

@TestInstance(Lifecycle.PER_METHOD)
public class MathUtilTest {
  
  private int result = 5;
  
  @Test
  void test_Add() {
    result = MathUtil.add(result, 5);
    System.out.println("test_Add(5,5) => "+result);
    assertEquals(10, result);
  }
  
  @Test
  void test_Multiply() {
    result = MathUtil.multiple(result, 5);
    System.out.println("test_Multiply(5,5) => "+result);
    assertEquals(25, result);
  }

  @Test
  void test_Devide() {
    result = MathUtil.devide(result, 5);
    System.out.println("test_Devide(5,5) => "+result);
    assertEquals(1, result);
  }  
}

test_Devide(5,5) => 1
test_Add(5,5) => 10
test_Multiply(5,5) => 25

Lifecycle per-class mode

• 테스트가 진행될 때 클래스 단위로 인스턴스 한번 생김

• non-static @BeforeAlland @AfterAll 사용가능

@TestInstance(Lifecycle.PER_CLASS)
public class MathUtilTest {
  
  private int result = 5;
  
  @Test
  void test_Add() {
    result = MathUtil.add(result, 5);
    System.out.println("test_Add(5,5) => "+result);
    assertEquals(10, result);
  }
  
  @Test
  void test_Multiply() {
    result = MathUtil.multiple(result, 5);
    System.out.println("test_Multiply(5,5) => "+result);
    assertEquals(25, result);
  }

  @Test
  void test_Devide() {
    result = MathUtil.devide(result, 5);
    System.out.println("test_Devide(5,5) => "+result);
    assertEquals(1, result);
  }  
}

test_Devide(5,5) => 1
test_Add(5,5) => 6
test_Multiply(5,5) => 30

Junit 5 - @TestInstance

In this quick guide, we discuss Junit 5 annotation and examples on how to change test instance lifecycle behaviour using @TestInstance. JUnit creates a new instance of each test class before executing each test method. The default behaviour of Junit 5 test instance lifecycle is "per-method". This can be changed using @TestInstance annotation.

https://javabydeveloper.com/junit-5-test-instance-lifecycle-with-examples/