In the evolving landscape of Java application development, particularly with Spring Boot, the importance of maintaining high-quality code cannot be overstated. A key aspect in achieving this is through effective code coverage. This comprehensive guide will delve into the why and how of code coverage in Java Spring Boot, including practical setups for popular tools, and a comparative analysis to help you choose the right tool for your needs.
The Importance of Code Coverage
Code coverage is a metric used to measure the percentage of source code executed by automated tests. It plays a critical role in software development for several reasons:
A Simple Java Spring Boot Code Snippet
Let's consider a basic <span class="pink">Calculator</span>
class in Java Spring Boot:
Unit Testing the Code Snippet
To ensure our <span class="pink">Calculator</span>
works as expected, we write JUnit tests:
Let's use the open source Unlogged IDE plugin to see how it makes unit testing easier. With the Unlogged plugin, you can:
To set up the plugin in the IntelliJ IDEA, go to File → Settings or IntelliJ IDEA → Settings on macOS.
Select Plugins, and search for "Unlogged".
Click Install. Once installed, the plugin will show an "Installed" status.
We need to add some new dependencies and a plugin item to our <span class="teal">pom.xml</span>
file.
Add these dependencies in the <span class="pink"><dependencies></span>
tag:
Run the Maven dependency resolve command to download the Unlogged dependencies and plugin:
You should see the <span class="teal">BUILD SUCCESS</span>result:
Finally, reload the project using the Maven plugin. Click the Maven icon on the right side of the IntelliJ IDEA window, then select the refresh icon.
Setting Up Code Coverage Tools
Maven: Add the following to your <span class="pink">pom.xml</span>
:
Gradle:
Include in your <span class="pink">build.gradle</span>:
Maven:
Insert into <span class="pink">pom.xml</span>, use with JDK 8:
Maven:
Add in <span class="pink">settings.xml</span> in .m2:
or
Note : <span class="pink">com.atlassian.maven.plugins</span> gives you access to Atlassian’s plugin which is now open source.
JaCoCo:
Maven: Run <span class="pink">mvn test jacoco:report</span>
Gradle: Run <span class="teal">./gradlew test jacocoTestReport</span>
Cobertura:
Maven: Run <span class="pink"mvn cobertura:cobertura</span>
Clover:
Maven: Run <span class="pink">mvn clover:setup test clover:aggregate clover:clover</span>
Unlogged:
Maven: Run <span class="pink">mvn test</span>
Gradle: Run <span class="teal">./gradlew test</span>
Code coverage is an indispensable tool in the Java Spring Boot developer's arsenal. Tools like Unlogged, JaCoCo, Cobertura, and Clover not only help in maintaining high-quality code but also encourage best practices in software development. By integrating these into your development workflow, you ensure robust, reliable, and maintainable Java Spring Boot applications.
Remember, while striving for high code coverage is important, the ultimate goal is to write effective tests that genuinely enhance the quality and reliability of your software.