[JAVA] Overwrite the contents of config with Spring-boot + JUnit5

Introduction

You can use it immediately if you use Mockito, but I wrote it because I wanted to make a note.

environment

Java9 Spring-boot 2.0.0.RELEASE

This goal

Rewrite the Config set in the Service class from Junit instead of reading the test Config file.

pom.xml It is written in other articles, but I will always check it, so I will write it in the meantime.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.tasogarei</groupId>
	<artifactId>junit-test</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>junit-test</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.0.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>9</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.platform</groupId>
            <artifactId>junit-platform-launcher</artifactId>
            <version>1.0.1</version>
            <scope>test</scope>
        </dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>

Service There is a mysterious private method, but I just want to try something else after this. please do not worry.

package com.tasogarei.app.service;

import java.util.Properties;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.tasogarei.app.util.TestConfig;

@Service
public class TestService {
    
    @Autowired
    private TestConfig config;
    
    public String getString() {
        return getStr();
    }
    
    private String getStr() {
        return config.getTest();
    }    
}

config This time, we will do it based on the Configuration annotation.

package com.tasogarei.app.util;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

@Configuration
public class TestConfig {
    @Value("${app.test}") 
    private String test;

    public String getTest() {
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }
}

application.properties

app.test=configtest

Put an appropriate value in ʻapplication.properties`.

Test class

If you convert it to Mock with @ MockBean and do the content you want to rewrite withMockito.when (). Then (), the one that was converted to Mock in the test will be used, so this is okay. Even if the return value of the method specified by when is a class, if you put the class you want to rewrite with then, that class will be used, so you can test with it. Of course the types must be the same.

package com.tasogarei.app.service;

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

import java.util.Properties;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit.jupiter.SpringExtension;

import com.tasogarei.app.util.TestConfig;

@ExtendWith(SpringExtension.class)
@SpringBootTest
public class TestServiceTest {

    @Autowired
    private TestService testService;
    
    @MockBean
    private TestConfig testConfig;
    
    @Test
    public void test() {
        Mockito.when(testConfig.getTest()).thenReturn("hogehoge123");
        assertEquals(testService.getString(), "hogehoge123");
    }
}

Finally

I feel that rewriting with the test method is subtle, so I think that it is better to do what can be done in advance processing there.