(Not affiliated with GitHub, Mojang or Microsoft)

At AmbleLabs (GitHub, Codeberg) we’ve been working hard on our first and most popular Minecraft mod Adventures in Time.

The mod is quite complex with about 100k lines of code.

We didn’t want to test stuff ourselves manually, and we wanted to use Minecraft’s gametest framework… And then we’ve realised that our Donators haven’t seen a beta build in weeks!

This wasn’t good.

Obviously, we had some basic CI that checked the build status, but this wasn’t enough.

Then I’ve had an idea: what if the build would automatically get built, tested and sent over to our Discord in a channel where donators (and, potentially, testers) could play with it!

And that’s what we’ve done:

name: Automated Builds

on:
  workflow_dispatch:
  push:
      paths:
        - src/**
        - build.gradle
        - gradle.properties
        - settings.gradle
        - gradle/**
        - gradlew
        - gradlew.bat
        - versioning.gradle
        - .github/workflows/publish-devbuilds.yml

jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read

    steps:
    - uses: actions/checkout@v4

    - name: Setup Gradle
      uses: gradle/actions/setup-gradle@v5
      with:
        cache-encryption-key: ${{ secrets.GRADLE_ENCRYPTION_KEY }}

    - name: Set up JDK 17
      uses: actions/setup-java@v4
      with:
        java-version: '21'
        distribution: 'temurin'
        cache: 'gradle'

    - name: Build
      run: ./gradlew --configuration-cache build

    - name: Publish artifacts
      uses: drtheodor/[email protected]
      with:
        url: ${{ secrets.DEV_BUILDS }}
        username: george washington
        avatar: 'https://i.imgur.com/uiFqrQh.png'
        
        message_commit: '> :sparkles: [${commitMessage}](<${commitUrl}>) by [${authorName}](<${authorUrl}>)'
        message_header: |
          <:new1:1253371736510959636><:new2:1253371805734015006> New `Adventures in Time` dev build `#${{ github.run_number }}`:

        file: |
          build/libs/*.jar
          !build/libs/*-sources.jar

The DEV_BUILDS secret here points to a Discord webhook url.

(!) Note

You can disable configuration cache if your build.gradle does not support it by removing the --configuration-cache argument. The build may fail if you try to build with configuration cache while having a buildscript that can’t be cached.

And voila, when changing any file listed in paths, the mod gets built and sent over to our Discord for people to test!

However, builds were still named the same. We couldn’t find out which commit people used… So we’ve changed our versioning behavior to be as follows:

versioning.gradle:

import java.util.Optional

class CI {

    static final String REFS_PREFIX = "refs/heads/"

    static Optional<String> branch() {
        // groovy is very bad at globals, apparently.
        return Optional.ofNullable(System.getenv("GITHUB_REF"))
                .filter { it.startsWith(REFS_PREFIX) }
                .map { it.substring(REFS_PREFIX.length()).replaceAll("/", "-") }
    }

    static Optional<String> buildNum() {
        return Optional.ofNullable(System.getenv("GITHUB_RUN_NUMBER"))
    }
}

class Versioning {

    static final String BRANCH_MAIN = "main"
    static final String BRANCH_RELEASE = "release"

    static final String BUILD_RELEASE = "release"
    static final String BUILD_LOCAL = "local"
    static final String BUILD = "dev"

    static Optional<String> getBranch() {
        return CI.branch()
                .filter { it != BRANCH_MAIN && it != BRANCH_RELEASE }
    }

    static Optional<String> getBuild() {
        return CI.branch()
                .filter { it != BRANCH_RELEASE }
                .flatMap { CI.buildNum() }
    }

    static String getQualifier() {
        return CI.branch()
                .map { it == BRANCH_RELEASE ? BUILD_RELEASE : BUILD }
                .orElse(BUILD_LOCAL)
    }
}

String createVer(boolean includeBuild) {
    String qualifier = ""

    Versioning.branch.ifPresent { branch ->
        qualifier += "$branch-"
    }

    qualifier += Versioning.qualifier

    Versioning.build.filter { includeBuild }.ifPresent {build ->
        qualifier += ".$build"
    }

    return "$project.mod_version-$qualifier+mc.$project.minecraft_version"
}

ext.getPublicVersion = {
    return createVer(true)
}

ext.getArtifactVersion = {
    return createVer(false)
}

Then just use it in build.gradle:

apply from: 'versioning.gradle'

version = getPublicVersion()

This uses the following properties:

mod_version = 1.2.13
mod_version_qualifier=release
minecraft_version=1.20.1

The resulting mod name turns out to be ait-1.2.13-build.1670-feat-chairs+mc.1.20.1.jar with the build number being the CI run number.

It also contains the branch name, which can be easily identified!