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.
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.
<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>
Gradle users can add the following dependency in the build.gradle file.
compile group: 'org.mockito', name: 'mockito-core', version: '2.13.0' 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.
package com.howcodex.mockitodemo; 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.
package com.howcodex.mockitodemo; 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 −
package com.howcodex.mockitodemo; 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.
package com.howcodex.mockitodemo; 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.
package com.howcodex.mockitodemo; 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
<?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.howcodex</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
buildscript { 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.howcodex' 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.
For Gradle, you can use the command as shown −
gradle clean build
You can see the rest results in console window.