An example with Spring-Boot module auto-discovery

ModuleTest.java

package com.josefczech.blog.examples.datajpatestflushandclear;

import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.databind.Module;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.json.JsonTest;
import org.springframework.boot.test.context.TestConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

@JsonTest
public class ModuleTest {
    @TestConfiguration
    static class TestConfig {
        @Bean
        public Module someModule() {
            return new Module() {
                @Override
                public String getModuleName() {
                    return "somemodule";
                }

                @Override
                public Version version() {
                    return new Version(1, 1, 1, "");
                }

                @Override
                public void setupModule(SetupContext context) {
                    // TODO
                }
            };
        }

        //@Bean // uncomment to disable module auto-discovery
        public Jackson2ObjectMapperBuilder jackson2ObjectMapperBuilder() {
            return new Jackson2ObjectMapperBuilder();
        }
    }

    @Autowired
    private ObjectMapper objectMapper;

    @Test
    public void test() {
        for (Object registeredModuleId : objectMapper.getRegisteredModuleIds()) {
            System.out.println(registeredModuleId);
        }
    }
}