Automated testing plays a vital role in the software industry. In this article, let us see how to do the testing using MockMvc for a Spring Boot project. To test the web layer, we need MockMvc and by using @AutoConfigureMockMvc, we can write tests that will get injected. SpringBootApplication is an excellent one that adds the following
- @Configuration
- @EnableAutoConfiguration
- @EnableWebMvc
- @ComponentScan
The application can ordinarily run as a Java application and hence development wise it is easier. Let’s see the concept via a sample project
Example Project
Project Structure:
As it is a maven project, all dependencies are available under
pom.xml
Dependencies like
- JDK 1.8
- Spring version from 2.2.5 onwards
- Maven 3.2+ and in the case of Gradle, it is Gradle 4+
We should add all the dependencies in pom.xml(in the case of the Maven project)
XML
<?xml version="1.0" encoding="UTF-8"?> xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 <modelVersion>4.0.0</modelVersion> <groupId>com.gfg.sample</groupId> <artifactId>sampleboot-unit-testing-with-mock-mvc</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <!-- Mandatory --> <version>2.2.5.RELEASE</version> </parent> <properties> <java.version>1.8</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> </dependency> </dependencies></project> |
We are using MockMvc to test the web layer. That is we should have a model. a controller, and a view. Let us see the controller file
WelcomeMvcController.java
Each and every method should have either Getmapping or Postmapping
Java
import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.GetMapping;@Controllerpublic class WelcomeMvcController { @Autowired private WelcomeService welcomeService; @GetMapping(value = "/") public String greeting1(String name, Model model) { model.addAttribute("welcome", welcomeService.greetingMessage1(name)); return "welcome-page"; } @GetMapping(value = "/event") public String greeting2(String name, Model model) { model.addAttribute("welcomeToEvent", welcomeService.greetingMessage2(name)); return "event-page"; }} |
Required services are written in the service file
WelcomeService.java
Java
import org.springframework.stereotype.Service;@Servicepublic class WelcomeService { public String greetingMessage1(String name) { return String.format("Welcome , %s to the world of programming!!!", name ); } public String greetingMessage2(String attendee) { return String.format("Welldone , %s You are selected to the contest!!!", attendee ); }} |
SpringBoot Application is run as an ordinary Java application only
WebAppMain.java
Java
import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublic class WebAppMain { public static void main(String[] args) { SpringApplication.run(WebAppMain.class, args); }} |
Now let us start to write the test class that tests the web layer by using MockMvc
WelcomeWebAppTest.java
Java
import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.test.context.junit4.SpringRunner;import org.springframework.test.web.servlet.MockMvc;import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;import org.springframework.test.web.servlet.result.MockMvcResultHandlers;import org.springframework.test.web.servlet.result.MockMvcResultMatchers;@RunWith(SpringRunner.class)@SpringBootTest@AutoConfigureMockMvcpublic class WelcomeWebAppTest { @Autowired private MockMvc mockMvc; @Test // We have to write out expectations and the // expectations need to match with actuals // When this is run, it imitates and accesses // the web layer and get the output. public void testWelcome() throws Exception { this.mockMvc.perform(MockMvcRequestBuilders.get("/").param("name", "Geeks")) .andExpect(MockMvcResultMatchers.status().isOk()) .andExpect(MockMvcResultMatchers.model().attribute("welcome", "Welcome , Geeks to the world of programming!!!")) .andExpect(MockMvcResultMatchers.view().name("welcome-page")) .andDo(MockMvcResultHandlers.print()); } @Test public void testWelcomeToEvent() throws Exception { this.mockMvc.perform(MockMvcRequestBuilders.get("/event").param("name", "Geeks")) .andExpect(MockMvcResultMatchers.status().isOk()) .andExpect(MockMvcResultMatchers.model().attribute("welcomeToEvent", "Welldone , Geeks You are selected to the contest!!!")) .andExpect(MockMvcResultMatchers.view().name("event-page")) .andDo(MockMvcResultHandlers.print()); }} |
Once the project is complete and does not contain any errors, we can run the test file as an ordinary JUNIT application
Console Output:
Once we are getting response 200 means the service is available and the parameters are passed properly and it is producing a positive response. With that response, we are comparing the details by means of
Java
this.mockMvc.perform(MockMvcRequestBuilders.get("/").param("name", "Geeks")) .andExpect(MockMvcResultMatchers.status().isOk()) // checking status .andExpect(MockMvcResultMatchers.model().attribute("welcome", "Welcome , Geeks to the world of programming!!!")) // sent attribute and its value check .andExpect(MockMvcResultMatchers.view().name("welcome-page")) // its view name check .andDo(MockMvcResultHandlers.print()); |
Like this, we can test the web layer in the above-said ways
Conclusion
Automated testing helps to avoid tons of errors and error-free code and helps for good quality software. In the Spring Boot project, we can use MockMvc and can achieve the same.
