Contributing to Apache Maven JMod Plugin

You have found a bug, or you have an idea for a cool new feature? Contributing code is a great way to give something back to the open source community. Before you dig right into the code, there are a few guidelines that we need contributors to follow so that we can have a chance of keeping on top of things.

Getting Started

• Make sure you have a GitHub account.
• If you're planning to implement a new feature, it makes sense to discuss your changes on the dev list first. This way you can make sure you're not wasting your time on something that isn't considered to be in Apache Maven's scope.
• Submit a ticket for your issue, assuming one does not already exist.
  • Clearly describe the issue, including steps to reproduce when it is a bug.
  • Make sure you fill in the earliest version that you know has the issue.
• Fork the repository on GitHub.

Making and Submitting Changes

We accept Pull Requests via GitHub. The developer mailing list is the main channel of communication for contributors.
There are some guidelines which will make applying PRs easier for us:

• Create a topic branch from where you want to base your work (this is usually the master branch). Push your changes to a topic branch in your fork of the repository.
• Make commits of logical units.
• Respect the original code style: by using the same codestyle, patches should only highlight the actual difference, not being disturbed by any formatting issues:
  • Only use spaces for indentation.
  • Create minimal diffs - disable on save actions like reformat source code or organize imports. If you feel the source code should be reformatted, create a separate PR for this change.
  • Check for unnecessary whitespace with git diff --check before committing.
• Make sure you have added the necessary tests (JUnit/IT) for your changes.
• Run all the tests with mvn -Prun-its verify to assure nothing else was accidentally broken.
• Submit a pull request to the repository in the Apache organization.
• Update your JIRA ticket and include a link to the pull request in the ticket.

If you plan to contribute on a regular basis, please consider filing a contributor license agreement.

Additional Resources

• Contributing patches
• Contributor License Agreement
• General GitHub documentation
• GitHub pull request documentation
• Apache Maven X Account
• Apache Maven Bluesky Account
• Apache Maven Mastodon Account

How to run Integration Tests with JDK 9

If you are running your Maven installation with a different JDK than JDK 9 you have give the JDK 9 path via the command line:

mvn clean verify -Prun-its -Dinvoker.javaHome=JDK9JAVAHOME

The reason behind this is simply cause Maven JMod Plugin will call jmod tool of the JDK which is needed to be found. Otherwise, none of the integration tests can work.