Build System Questions: KTS Migration & Multiple Build Systems

[eshaffer321]

Hey @esaulpaugh!

1. There's a build.gradle.kts file that's completely commented out, was there an incomplete migration to Gradle KTS that got abandoned?

2. The project has configs for Gradle, Maven, and Ant. Is there a recommended build system, or any particular reason to support all three?

Just trying to understand the current state and what the preferred approach is for new contributors. Thanks!

[esaulpaugh]

Hey @eshaffer321.

I have four independent build systems (crazy thing to do), but it should mean that the project will remain buildable at all times, without modifications, via at least one of them. Also, people get picky about build systems so I figured I would support all the major ones and people can choose. So there is build.gradle, build.gradle.kts, pom.xml, and build.xml.

1. The Gradle Kotlin DSL script is commented out to avoid confusion as to which script runs when executing tasks with gradle or ./gradlew. It wasn't so much a migration as an alternative for people who prefer it to groovy gradle. To use it, you must delete build.gradle locally first. The only annoying thing is that, despite all efforts, the kts build must make use of a plugin id("me.champeau.jmh").version("0.7.2") to get jmh to work properly and I'm not sure why. But that's just an implementation detail. Also this script requires gradle 7+ whereas build.gradle only requires 4.6+.
2. My preferred build process is to use the latest JDK 11 (currently 11.0.27) and do gradle build because, due to a combination of factors, the resulting jar is the smallest that way (not by that much).

I may as well note that only the maven build can put the JMH benchmarks into an executable jar file.

I also try to support as many versions of gradle and maven as I can. Maven v3.6.3+ and Gradle v4.6+ should work. I'm not sure of the oldest version of ant which could run the build.xml, though. I do the same with the gson version which can be as low as v2.1 at runtime (but v2.12.0+ required at compile time).

[esaulpaugh]

Also JUnit 5.12.x+ is not as compatible with older versions of maven plugins (just surefire?), and maybe older gradle versions, so I'm not sure whether or how to upgrade from JUnit 5.11.4 without harming compatibility. I believe it's related to junit-platform-launcher.