Building and testing

Requirements#

The build sets a Java toolchain explicitly:

java {
    toolchain {
        languageVersion = JavaLanguageVersion.of(25)
    }
}

The two Gradle builds#

The repository has two Gradle projects.

Both compile the same core sources. The root project adds src/neoforge/java and one compat source set; the Fabric project adds fabric/src/main/java and its own compat source set.

sourceSets {
    main {
        java {
            srcDirs = ['src/main/java', 'src/neoforge/java', 'src/compat/mc26_2/java']
        }
    }
}

Building#

NeoForge, Minecraft 26.2#

$ ./gradlew build

Fabric, Minecraft 26.3#

$ cd fabric && ./gradlew build

Fabric, Minecraft 26.2#

$ ./gradlew build -Pminecraft_version=26.2 "-Pminecraft_version_range=>=26.2 <26.3" -Pfabric_version=0.161.0+26.2

On Windows, use gradlew.bat instead of ./gradlew.

Where the jars land#

The version string comes from gradle.properties and carries the loader flavour, for example 4.1.2-alpha-fabric or 4.1.2-alpha-nf-mc262.

Running the tests#

$ cd fabric && ./gradlew test

There are 16 test classes in fabric/src/test/java/dev/inputbooster:

The changelog for 4.1.0-alpha records 81 tests in total.

The two tests that guard the mod#

MixinDeclarationTest and MixinTargetSignatureTest exist because of two release-stopping crashes.

MixinDeclarationTest fails the build if a registered mixin declares a non-private static method. Mixin only permits private static helpers inside a mixin, and a public one aborts the transformation of the whole target class. That bug shipped in 4.0.2-stable and crashed every client before the main menu.

MixinTargetSignatureTest checks every @Inject, @Accessor and @Invoker against the resolved Minecraft jar, for both the 26.2 and 26.3 builds. It exists because 4.1.0-alpha crashed on every loader: the keyboard mixin was written against the 1.21 signature keyPress(long, int, int, int, int) while 26.2 and 26.3 use keyPress(long, int, KeyEvent).

CI#

The gradle.yml workflow runs on pushes to main and fabric-26.2-26.3, on v* tags, on pull requests targeting main, and through manual workflow dispatch.

The Fabric job verifies the dependency range form before it uploads anything:

grep -q '"minecraft": *">=' /tmp/fabric.mod.json \
  || { echo "minecraft dependency must use the '>=x <y' form" >&2; exit 1; }

The release job refuses to publish unless all three jars are present, derives the tag from mod_version when there is no explicit tag, and marks a release as a prerelease when the version contains alpha or beta.

Fabric unit tests and build matrix#

The test.yml workflow adds a dedicated Fabric test-and-build job. It runs on pushes to main and fabric-26.2-26.3 when files under fabric/ or src/, or the workflow itself, change. It can also be started manually from GitHub Actions.

Each matrix job uses Temurin Java 25 and runs ./gradlew clean test build --no-daemon from fabric/, passing the matching Minecraft version, dependency range and Fabric API version. JUnit reports are uploaded even when a test fails; the Fabric jar is uploaded only after a successful build. Both artifact types are retained for 14 days.

Headless client smoke test#

The client-smoke.yml workflow uses the same two-version Fabric matrix and push/path filters, and also supports manual dispatch. It starts runClient under Xvfb with Mesa software rendering and a null audio backend, so CI does not need a physical display or audio device.

The check waits up to 210 seconds for the client log marker Sound engine started, then verifies that the client remains running for another 10 seconds. It uploads the client console, game logs and crash reports for 14 days.

Running the mod in a development client#

Both Gradle projects define a client run configuration:

./gradlew runClient

The NeoForge root project sets neoforge.enabledGameTestNamespaces to the mod id, so game tests in that namespace run in the development client.

Related pages#

• Architecture — the source layout.
• Mixin inventory — what the signature test checks.
• Versioning — how version numbers map to jars.