jUnit Spring Batch 5

I have this class:

    package com.example.demo;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.job.builder.JobBuilder;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.batch.core.step.builder.StepBuilder;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.PlatformTransactionManager;

@Configuration
public class JobConfiguration {

    @Bean
    public Job job(JobRepository jobRepository, PlatformTransactionManager transactionManager) {
        return new JobBuilder("job", jobRepository)
                .start(new StepBuilder("step", jobRepository)
                        .tasklet((contribution, chunkContext) -> {
                            System.out.println("hello world");
                            return RepeatStatus.FINISHED;
                        }, transactionManager)
                        .build())
                .build();
    }
}

I would like to create class JobConfigurationTest to test with jUnit. can you help me please (how to mock 'PlatformTransactionManager ')

Solution

firstly, you should follow program to interface rule which's mean you should change method signature job(JobRepository jobRepository, TransactionManager transactionManager) so it'll be easy to test like following

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 org.springframework.batch.core.Job;
import org.springframework.batch.core.repository.JobRepository;
import org.springframework.transaction.TransactionManager;

import static org.junit.jupiter.api.Assertions.assertNotNull;

@ExtendWith(MockitoExtension.class)
public class JobConfigurationTest {

    @Mock
    private JobRepository jobRepository;

    @Mock
    private TransactionManager transactionManager;

    @InjectMocks
    private JobConfiguration jobConfiguration;

    @Test
    public void testJobConfiguration() {
        Job job = jobConfiguration.job(jobRepository, transactionManager);
        assertNotNull(job, "Job should not be null");
    }
}