OpenClover - Getting to work with AspectJ

Question

I'm trying to use Openclover with a project that uses AspectJ and that instruments aspects into its code.

The pom.xml has these dependencies with relation to AspectJ:

...
<dependencies>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.8.9</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjrt</artifactId>
        <version>1.8.9</version>
        <scope>provided</scope>
    </dependency>
</dependencies>
...

And these plugins:

    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>aspectj-maven-plugin</artifactId>
        </plugin>

        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
        </plugin>

        <plugin>
            <groupId>org.openclover</groupId>
            <artifactId>clover-aspectj-compiler</artifactId>
            <version>1.0.0</version>
        </plugin>

        <plugin>
            <groupId>org.openclover</groupId>
            <artifactId>clover-maven-plugin</artifactId>
            <version>4.2.0</version>
            <executions>
                <execution>
                    <id>clover</id>
                    <phase>verify</phase>
                    <goals>
                        <goal>instrument</goal>
                        <goal>clover</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>

I'm using two plugins to do this: clover-maven-plugin which is a code coverage tool and clover-aspectj-compiler, a wrapper for AspectJ compiler which allows code instrumentation using OpenClover.

The errors I get are the following:

[ERROR] QueryAspect.java:48:0::0 The type QueryAspect is already defined
[ERROR] LogAspect.java:35:0::0 The type LogAspect is already defined

The documentation about this is just too little (or better, none) and I can't seem to make AspectJ work with OpenClover, and there isn't much help on the web.

Thank you

Answer 1

As discussed in our comments, you can just use AspectJ Maven instead of Clover AspectJ. You just need to take a few precautions in order to get it to work:

• I like to put AspectJ Maven executions into the process-sources phase in order to make sure the AspectJ compiler kicks in before the normal Java compiler kicked off by Maven Compiler plugin. You could also deactivate Maven Compiler instead as Ajc is a full replacement for Javac. Actually that phase used to be the default in older plugin versions, but it has been changed long ago, which is also mentioned in an answer on SO.

• There is a problem in Maven Compiler, namely the switch useIncrementalCompilation seems to have reversed logic. This is why you need to set it to false in order to make it work. Otherwise it tries to recompile stuff already compiled by AspectJ, breaking aspect weaving. See MCOMPILER-209 and MCOMPILER-194, I explained the problem and its solution there in my posts.

• Now the only issue actually related to OpenClover (OC): AspectJ (AJ) does not know anything about OC adding source code to each method in order to enable code coverage. Unfortunately OC also does not know about AJ and also adds code to annotation-style pointcuts defined as empty methods with a @Pointcut annotation. As OC needs to do its magic before AJ compiles, the AJ compiler complains about unexpected code found in the pointcut and stops compilation with an error. There are at least two ways to avoid that:

  • You can either inline all pointcuts into the respective @Before, @After, @Around etc. advices using them, which usually works, but is not always an option in cases where you need argument binding in pointcuts in order to implement a wormhole pattern like execution(pointcutA()) && cflow(execution(pointcutB(myArgument))).

  • Or you can exclude all aspects from OC instrumentation, which is easiest if they reside in one package where there are no other Java classes which need to be instrumented. Then you can use a simple exclusion like in your case <exclude>codeaspects/**</exclude>. This is what I was doing in my pull request when fixing your project.

  • The easiest way is to just rename all aspects from *.java to *.aj, which is the canonical way of naming them anyway. I just tried in your project, and it works beautifully. AspectJ Maven looks for those files anyway, but OC will ignore them, not even calculating their lines of code for missing coverage. You can also get rid of the <exclude> mentioned above, see this commit.

Maybe all of this is automatically taken care of by Clover AspectJ, I never tried. Maybe the author of that compiler wrapper should actually explain what it does and how it works in the documentation, especially how to use it with Maven. Otherwise it does not make much sense to use it.