Gradle7 Version Catalog: How to use it with buildSrc? - gradle

Question

I am very excited about the incubating Gradle's version catalogs and have been experimenting with it. I’ve found that the information in my gradle/libs.versions.toml is accessible in the build.gradle.kts scripts for my app and utility-lib projects.
However, I am unable to use the content of the toml file for buildSrc/build.gradle.kts or the convention files.
The only way that I could build was to hard-code the dependencies into those files, as I did before the version catalog feature.
In the buildSrc folder, I created a settings.gradle.kts file and inserted the dependencyResolutionManagement code for versionCatalogs, which is pointing to the same file as for my app and utility-lib projects.
Based on the Gradle7 docs, it seems that sharing a version catalog with buildSrc and modules is possible… I’d appreciate a nudge into getting it to work with buildSrc, if possible.
Here is a simple sample project, which I created via gradle init: my-version-catalog
Thank you for your time and help,
Mike

Answer 1

With Gradle 7.3.3, it is possible. Note version catalogs are GA since Gradle 7.4
The code snippet assumes Gradle is at least 7.4, but if you need them prior that version, insert enableFeaturePreview("VERSION_CATALOGS") at the beginning of each settings.gradle.kts.
Using buildSrc
buildSrc/settings.gradle.kts
dependencyResolutionManagement {
versionCatalogs {
create("libs") {
from(files("../gradle/libs.versions.toml"))
}
}
}
buildSrc/build.gradle.kts
dependencies {
implementation(libs.gradleplugin.intellij) // <- the lib reference
}
You can even use the version catalog for plugins
gradle/libs.versions.toml
...
[plugins]
kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
jetbrains-changelog = { id = "org.jetbrains.changelog", version.ref = "changelog-plugin" }
jetbrains-intellij = { id = "org.jetbrains.intellij", version.ref = "intellij-plugin" }
hierynomus-license = { id = "com.github.hierynomus.license", version.ref = "license-plugin" }
nebula-integtest = { id = "nebula.integtest", version.ref = "nebula-integtest-plugin" }
build.gradle.kts
plugins {
id("java")
alias(libs.plugins.kotlin.jvm)
alias(libs.plugins.nebula.integtest)
alias(libs.plugins.jetbrains.intellij)
alias(libs.plugins.jetbrains.changelog)
alias(libs.plugins.hierynomus.license)
}
Note for accessing the catalog within scripts, please refer to the below section, the trick is the same.
Using convention plugins and included build
In the main project include a the Gradle project that holds the convention plugins.
build.gradle.kts
includeBuild("convention-plugins") // here it's a subfolder
convention-plugins/settings.gradle.kts
dependencyResolutionManagement {
repositories {
gradlePluginPortal()
}
versionCatalogs {
create("libs") {
from(files("../gradle/libs.versions.toml"))
}
}
}
rootProject.name = "convention-plugins"
The trick to enable convention plugins to access the version catalog is split in two part, add an ugly implementation dependency that locate where the version catalog generated classes are located.
libs.javaClass.superclass.protectionDomain.codeSource.location
Then in the convention plugin refer to the libs extension via Project::the.
val libs = the<LibrariesForLibs>()
This is tracked by gradle/gradle#15383.
convention-plugins/build.gradle.kts
plugins {
`kotlin-dsl`
}
dependencies {
implementation(libs.gradleplugin.kotlin.jvm)
// https://github.com/gradle/gradle/issues/15383
implementation(files(libs.javaClass.superclass.protectionDomain.codeSource.location))
}
And in the actual convention plugin
import org.gradle.accessors.dm.LibrariesForLibs
plugins {
id("org.jetbrains.kotlin.jvm")
}
// https://github.com/gradle/gradle/issues/15383
val libs = the<LibrariesForLibs>()
dependencies {
detektPlugins(libs.bundles.kotlinStuff) // access catalog entries
}
The org.gradle.accessors.dm.LibrariesForLibs class is generated by gradle is somewhere in local gradle folder ./gradle/<version>/dependency-accessors/<hash>/classes
Quick note that older IntelliJ IDEA currently (2022.3) reports alias(libs.gradleplugin.thePlugin) as an error in the editor,
although the dependencies are correctly resolved.
This tracked by KTIJ-19369, the ticket indicates this is actually a bug in Gradle Kotlin DSL gradle/gradle#22797, and someone made a simple IntelliJ IDEA plugin to hide this error until resolved.

Answer 2

Brice, it looks like a can of worms to go down that path, particularly for my situation, where I'm trying to use a libs.version.toml file from an android project, but the custom plugin is of course from a java/kotlin project. I tried creating the libs file by hardwiring the path to the toml file in the custom plugin. It might work if both were java projects, but I never tried that since that's not what I'm after. The ideal solution would be for the plugin to use the libs file from the project it is applied to, but it looks like the version catalog needs to be created in the settings file, before you even have access to "Project", so that's why you would have to hardwire the path.
Short answer. No, but there are other techniques for a custom plugin to get project version data from the project it is applied to.