Project reports provide metadata about a project. This information answers questions like these:

• What is the test coverage?
• How well does the code adhere to the given coding standards?
• By which parameters has the project been built?
• What has been changed since the last release?
• What is the meaning of error codes issued by the library/application?
• By what properties can the library/application be configured?

The answers provide transparency to users of the project.

Attaching Metadata

Report information rendered in a project site makes it easily readable for humans. If you want to use some of this data in your build process, an easily parsable format would be much more convenient than grabbing the information from an HTML page. If the metadata is attached like a Maven site and stored in the artifact repository, writing plugins that read and display this information would be very comfortable. It also allows to mashup figures from different reports, even different projects, and draw new conclusions.

Aggregation Reports

In a multi project configuration Maven already allows to aggregate reports. This is useful since questions about quality metrics are often directed to the whole project and not only to its parts. There should be one report on code coverage to consult with no need to traverse the submodules individually.

What is true for a multi project configuration is also true for a more loosely coupled project spanning multiple individual projects. This is either necessary, since each project has its own lifecycle, or just convenient, because loosely coupled projects follow the delivery pipeline principle (please refer to Jez Humble in Continuous Delivery: Anatomy of the Deployment Pipeline) easily:

Loosely coupled projects help to reduce the complexity and increase the speed of release builds. If the release of a large project can be built on top of released sub projects, the release is much easier to handle. The drawback is that you have to deal with releasing multiple projects before you are able to release your whole product. Running a release must be reduced to a non-event to handle this appropriately.

Support by Maven Reports

While some Maven plugins, like the Maven Javadoc Plugin provide means to create an aggregate report for projects that are not part of a multi module build (please refer to Aggregating Javadocs from Dependency Sources for details), some reports don’t. For some reports it would be easy to merge report data. An issues report may merge issues marked as ‘new-and-noteworthy’ into a global new and noteworthy report. Other reports may need to be restructured to run on pre-generated report results.

Maven Plugin to attach Metadata

The next step is to make this information available with the semantic web. Until then, the Projectmetadata Maven Plugin allows to gather project metadata and make it accessible due to attached project artifacts.