Code Coverage Report Generation using JaCoCO

   Given the importance  given to the Unit and Integration tests , it is important to evaluate the amount of code that our test cases cover. The contenders  for tool of choice were Emma, Cobertura and JACOCO (sure has a strange name than others,it is actually JAva COde COverage). JACOCO won for the following reasons 

• While Emma and Cobertura have been around for long time they are not much efficient in collecting run time coverage data from a test running inside the container. JACOCO is made for it.
• They also do cool stuffs like on the fly Instrumentation of classes
• They work hand in hand with Arquillian  etc etc
• You can read further @ http://www.eclemma.org/jacoco/

 The generated report is very detailed, refer to the screen shots below (classified certain areas of screen print to honor NDA)

Project Level

Package level

Class level

Method Level

Highlighted in GREEN is covered code.
This report should help us to really write quality tests and in turn deliver a quality product.Now lets see how to set this up.


JACOCO Setup.

You will be so surprised that it is so simple with maven. add the following to your pom and thats it, yes really thats it. Your unit and integration tests coverage reports are ready.
Add the following dependency

<dependency>
   <groupId>org.jacoco</groupId>
   <artifactId>org.jacoco.core</artifactId>
   <version>0.5.3.201107060350</version>
   <scope>test</scope>
  </dependency>

and this

<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.5.3.201107060350</version>
    <executions>
     <execution>
      <id>jacoco-initialize</id>
      <goals>
       <goal>prepare-agent</goal>
      </goals>
     </execution>
     <execution>
      <id>report</id>
      <phase>install</phase>
      <goals>
       <goal>report</goal>
      </goals>
     </execution>
    </executions>
  </plugin> 

 Suggestions and user experience are welcome