Demo Build and Test via Pipeline

In this guide, we’ll extend our Jenkins pipeline by adding Build and Unit Test stages alongside the existing Echo Version step. By the end, you’ll have an automated flow that compiles, packages, and tests your Spring Boot application.

Current Pipeline Status

Below is the current pipeline, which installs Maven and echoes its version:

Application Repository

Our sample Spring Boot “Hello World” application resides in the jenkins-hello-world repository. It uses Maven to build a JAR and includes six JUnit test cases (five passing, one failing).

Defining the Pipeline

Create or update a Jenkinsfile at the root of your project with the following content:

pipeline {
    agent any

    tools {
        // Install the Maven version configured as "M398"
        maven "M398"
    }

    stages {
        stage('Echo Version') {
            steps {
                sh 'echo Print Maven Version'
                sh 'mvn -version'
            }
        }

        stage('Build') {
            steps {
                // Clone the repository (defaults to branch "master")
                git 'http://139.84.159.194:5555/dasher-org/jenkins-hello-world.git'
                // Build without running tests
                sh 'mvn clean package -DskipTests=true'
            }
        }

        stage('Unit Test') {
            steps {
                // Execute JUnit tests
                sh 'mvn test'
            }
        }
    }
}

Pipeline Stages Overview

First Run: Checkout Failure

On the initial run, the pipeline fails at the Build stage because the default branch is main, not master:

The console logs display:

ERROR: Couldn't find any revision to build. Verify the repository and branch configuration for this job.

Specifying the Correct Branch

Use the Jenkins Snippet Generator to craft a branch-specific git checkout:

1. Select Git.
2. Enter your repository URL.
3. Set Branch to main.
4. Click Generate Pipeline Script.

Adjust your Jenkinsfile:

git branch: 'main', url: 'http://139.84.159.194:5555/dasher-org/jenkins-hello-world.git'

Commit and re-run the pipeline. The checkout and build succeed, but one unit test still fails:

[ERROR] Tests run: 6, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 3.539 s <<< FAILURE! 
java.lang.AssertionError:
Expected: a string starting with "Hola"
     but: was "Hello, KodeKloud community!"

Fixing the Unit Test

Update the assertion in HelloControllerTests.java to match the controller’s greeting:

@Test
public void welcome_startsWithExpectedGreeting() throws Exception {
    mvc.perform(MockMvcRequestBuilders.get("/hello")
            .accept(MediaType.APPLICATION_JSON))
       .andExpect(status().isOk())
       .andExpect(content().string(startsWith("Hello")));
}

Commit the change and trigger the pipeline again. All stages should now pass:

Application Overview

Controller (src/main/java/com/kodekloud/hello_demo/HelloController.java):

package com.kodekloud.hello_demo;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    @RequestMapping("/hello")
    String hello() {
        return "Hello, KodeKloud community!";
    }
}

Configuration (src/main/resources/application.properties):

spring.application.name=hello-demo
server.port=6767

Next Steps

With this pipeline, you’ve automated:

1. Tool installation and version verification
2. Source checkout (branch main)
3. Maven clean package (skipping tests)
4. JUnit test execution

Consider adding stages for artifact archiving, static code analysis, or deployment.

Links and References

• Jenkins Pipeline Syntax
• Maven User Guide
• JUnit 5 Documentation