Unit Testing is a one of the testing done by the developers to make sure individual unit or component functionalities are working fine.
In this tutorial, we are going to see how to write a unit test case by using Mockito and Web Controller.
Mockito
For injecting Mockito Mocks into Spring Beans, we need to add the Mockito-core dependency in our build configuration file.
Maven users can add the following dependency in your pom.xml file.
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>2.13.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
Gradle users can add the following dependency in the build.gradle file.
testCompile('org.springframework.boot:spring-boot-starter-test')
The code to write a Service class which contains a method that returns the String value is given here.
import org.springframework.stereotype.Service;
@Service
public class ProductService {
public String getProductName() {
return "Honey";
}
}
Now, inject the ProductService class into another Service class file as shown.
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
@Service
public class OrderService {
@Autowired
ProductService productService;
public OrderService(ProductService productService) {
this.productService = productService;
}
public String getProductName() {
return productService.getProductName();
}
}
The main Spring Boot application class file is given below −
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class MockitoDemoApplication {
public static void main(String[] args) {
SpringApplication.run(MockitoDemoApplication.class, args);
}
}
Then, configure the Application context for the tests.
The @Profile(“test”) annotation is used to configure the class when the Test cases are running.
import org.mockito.Mockito;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.context.annotation.Profile;
@Profile("test")
@Configuration
public class ProductServiceTestConfiguration {
@Bean
@Primary
public ProductService productService() {
return Mockito.mock(ProductService.class);
}
}
Now, you can write a Unit Test case for Order Service under the src/test/resources package.
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@SpringBootTest
@ActiveProfiles("test")
@RunWith(SpringJUnit4ClassRunner.class)
public class MockitoDemoApplicationTests {
@Autowired
private OrderService orderService;
@Autowired
private ProductService productService;
@Test
public void whenUserIdIsProvided_thenRetrievedNameIsCorrect() {
Mockito.when(productService.getProductName()).thenReturn("Mock Product Name");
String testName = orderService.getProductName();
Assert.assertEquals("Mock Product Name", testName);
}
}
The complete code for build configuration file is given below.
Maven – pom.xml
<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.javahubpoint</groupId>
<artifactId>mockito-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>mockito-demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.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>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>2.13.0</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Gradle – build.gradle
ext {
springBootVersion = '1.5.9.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
group = 'com.javahubpoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}
dependencies {
compile('org.springframework.boot:spring-boot-starter')
compile group: 'org.mockito', name: 'mockito-core', version: '2.13.0'
testCompile('org.springframework.boot:spring-boot-starter-test')
}
You can create an executable JAR file, and run the Spring Boot application by using the following Maven or Gradle1 commands.
For Maven, you can use the command as shown −
mvn clean install
You can see the test results in console window.
Test Results in Console Window
For Gradle, you can use the command as shown −
gradle clean build
You can see the rest results in console window.
Rest Results in Console Window