MS Lesson 19: Unit Test

1. Unit test klasinin uzerine: @ExtendWith(MockitoExtension.class) 

2. 

package guru.springframework.cruddemo.testing;

import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)
public class CalculatorServiceTest {

    @InjectMocks
    private CalculatorService calculatorService;

    @Test
    public void whenSumTwoNumbersThenSuccess() {
        // Arrange

        // Act
        int result = calculatorService.sum(5, 7);

        // Assert
        Assertions.assertThat(result).isEqualTo(12);
    }

}

3.

package guru.springframework.cruddemo.testing;

import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)
public class CalculatorServiceTest {

    @InjectMocks
    private CalculatorService calculatorService;

    @Test
    public void whenSumTwoNumbersThenSuccess() {
        // Arrange

        // Act
        int result = calculatorService.sum(5, 7);

        // Assert
        Assertions.assertThat(result).isEqualTo(12);
    }

    @Test
    public void whenFirstDivideSecondThenSuccess() {
        // Arrange

        // Act
        int result = calculatorService.divide(10, 2);

        // Assert
        Assertions.assertThat(result).isEqualTo(5);
    }

    @Test
    public void whenFirstDivideToZeroThenException() {
        // Arrange

        // Act

        // Assert
        Assertions.assertThatThrownBy(() -> calculatorService.divide(5, 0))
                .isInstanceOf(ArithmeticException.class)
                .hasMessage("/ by zero");
    }

}

4. Parametrized test

@ParameterizedTest(name = "sum({0}, {1}) should be {2}")
@CsvSource({
        "5, 7, 12",
        "0, 0, 0",
        "-1, 1, 0",
        "100, 200, 300"
})
void whenSumTwoNumbersThenSuccess(int first, int second, int expected) {
    int result = calculatorService.sum(first, second);

    Assertions.assertThat(result).isEqualTo(expected);
}

5. 

package guru.springframework.cruddemo.service.impl;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.util.Optional;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import guru.springframework.cruddemo.dto.response.AccountResponse;
import guru.springframework.cruddemo.entity.Account;
import guru.springframework.cruddemo.mapper.AccountMapperMapstruct;
import guru.springframework.cruddemo.repository.AccountRepository;

@ExtendWith(MockitoExtension.class)
class AccountServiceImplTest {

    @Mock
    private AccountRepository accountRepository;

    @Mock
    private AccountMapperMapstruct mapperMapstruct;

    @InjectMocks
    private AccountServiceImpl accountService;

    @Test
    void getById_whenAccountExists_returnsMappedResponse() {
        // Arrange
        Long id = 1L;
        Account account = new Account();
        account.setId(id);
        account.setName("Ali");

        AccountResponse expected = new AccountResponse();
        expected.setName("Ali");

        when(accountRepository.findById(id)).thenReturn(Optional.of(account));
        when(mapperMapstruct.toResponse(account)).thenReturn(expected);

        // Act
        AccountResponse result = accountService.getById(id);

        // Assert
        assertThat(result).isEqualTo(expected);
        verify(accountRepository, times(1)).findById(id);
        verify(mapperMapstruct, times(1)).toResponse(account);
    }

    @Test
    void getById_whenAccountNotFound_throwsRuntimeException() {
        Long id = 99L;
        when(accountRepository.findById(id)).thenReturn(Optional.empty());

        assertThatThrownBy(() -> accountService.getById(id))
                .isInstanceOf(RuntimeException.class)
                .hasMessage("-------> Xeta");

        verify(mapperMapstruct, never()).toResponse(any());
    }

}