Contributing to Flatmap

Pull requests are welcome! To set up your development environment:

Fork the repo
Install Java 16 or later
Build and run the tests (mvnw automatically downloads maven the first time you run it):
- on max/linux: ./mvnw clean test
- on windows: mvnw.cmd clean test
- or if you already have maven installed globally on your machine: mvn clean test

To edit the code:

Install IntelliJ IDE
In IntelliJ, click Open, navigate to the the pom.xml file in the local copy of this repo, and Open then Open as Project
- If IntelliJ asks (and you trust the code) then click Trust Project
- If any java source files show "Cannot resolve symbol..." errors for Flatmap classes, you might need to select: File -> Invalidate Caches... -> Just Restart.
- If you see a "Project JDK is not defined" error, then choose Setup SDK and point IntelliJ at the Java 16 or later installed on your system
To verify everything works correctly, right click on flatmap-core/src/test/java folder and click Run 'All Tests'

Any pull request should:

Include at least one unit test to verify the change in behavior
Include an end-to-end test in FlatmapTests.java to verify any major new user-facing features work
Use IntelliJ's auto-formatting for modified files (this should get enabled automatically)
Be free of IntelliJ warnings for modified files

GitHub Workflows will run regression tests on any pull request.

TODO: Set up checkstyle and an auto-formatter to enforce standards, so you can use any IDE.