diff --git a/build.gradle.kts b/build.gradle.kts
index d9a35588..7981f50c 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -4,7 +4,7 @@ plugins {
 }
 
 // maven.repo.local is set within the Julia script in the website branch
-tasks.create("publishAllMavens") {
+tasks.register("publishAllMavens") {
     dependsOn(":forge:publishAllMavens")
     dependsOn(":neoforge:publishAllMavens")
 }
diff --git a/buildSrc/src/main/kotlin/kff.combined-conventions.gradle.kts b/buildSrc/src/main/kotlin/kff.combined-conventions.gradle.kts
index 22c078a7..d3d3ecac 100644
--- a/buildSrc/src/main/kotlin/kff.combined-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/kff.combined-conventions.gradle.kts
@@ -18,17 +18,4 @@ project.tasks.withType<Jar> {
             zipTree(project(":neoforge:$subproject").tasks.getByName("jar", Jar::class).archiveFile),
         )
     })
-
-    manifest {
-        attributes(
-            "Specification-Title" to "Kotlin for Forge",
-            "Specification-Vendor" to "Forge",
-            "Specification-Version" to "1",
-            "Implementation-Title" to project.name,
-            "Implementation-Version" to project.version,
-            "Implementation-Vendor" to "thedarkcolour",
-            "Implementation-Timestamp" to LocalDateTime.now(),
-            "Automatic-Module-Name" to "thedarkcolour.kotlinforforge.$subproject",
-        )
-    }
-}
\ No newline at end of file
+}
diff --git a/buildSrc/src/main/kotlin/kff.common-conventions.gradle.kts b/buildSrc/src/main/kotlin/kff.common-conventions.gradle.kts
index b1b62d62..3b8f9348 100644
--- a/buildSrc/src/main/kotlin/kff.common-conventions.gradle.kts
+++ b/buildSrc/src/main/kotlin/kff.common-conventions.gradle.kts
@@ -1,12 +1,13 @@
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
-import thedarkcolour.kotlinforforge.plugin.alias
+import org.jetbrains.kotlin.gradle.tasks.KotlinJvmCompile
 import thedarkcolour.kotlinforforge.plugin.getPropertyString
 
-project.plugins.apply(JavaPlugin::class)
-project.plugins.apply(IdeaPlugin::class)
-project.plugins.apply(MavenPublishPlugin::class)
-project.plugins.apply(alias("kotlinJvm", project))
+plugins {
+    java
+    idea
+    `maven-publish`
+    kotlin("jvm")
+}
 
 val jvmTarget = JvmTarget.JVM_17
 
@@ -32,7 +33,7 @@ project.tasks {
             expand(replacements)
         }
     }
-    withType<KotlinCompile> {
+    withType<KotlinJvmCompile> {
         compilerOptions.jvmTarget.set(jvmTarget)
         compilerOptions.freeCompilerArgs.set(listOf("-Xexplicit-api=warning", "-Xjvm-default=all"))
     }
diff --git a/combined/build.gradle.kts b/combined/build.gradle.kts
index 582984a3..93dcea4d 100644
--- a/combined/build.gradle.kts
+++ b/combined/build.gradle.kts
@@ -113,8 +113,8 @@ modrinth {
     loaders.add("neoforge")
     uploadFile.provider(project(":combined").tasks.jarJar)
 }
-tasks.create("publishModPlatforms") {
-    finalizedBy(tasks.create("printPublishingMessage") {
+tasks.register("publishModPlatforms") {
+    finalizedBy(tasks.register("printPublishingMessage") {
         doFirst {
             println("Publishing Kotlin for Forge ${getPropertyString("kff_version")} to Modrinth and CurseForge")
         }
diff --git a/forge/build.gradle.kts b/forge/build.gradle.kts
index 92520688..686d1ad2 100644
--- a/forge/build.gradle.kts
+++ b/forge/build.gradle.kts
@@ -1,5 +1,4 @@
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import thedarkcolour.kotlinforforge.plugin.getKffMaxVersion
 import thedarkcolour.kotlinforforge.plugin.getPropertyString
 
@@ -106,15 +105,17 @@ tasks {
         }
     }
 
-    withType<KotlinCompile> {
-        compilerOptions.jvmTarget.set(JvmTarget.JVM_17)
-    }
-
     assemble {
         dependsOn(jarJar)
     }
 }
 
+kotlin {
+    compilerOptions {
+        jvmTarget = JvmTarget.JVM_17
+    }
+}
+
 publishing {
     publications {
         register<MavenPublication>("maven") {
@@ -126,9 +127,9 @@ publishing {
 }
 
 // maven.repo.local is set within the Julia script in the website branch
-tasks.create("publishAllMavens") {
+tasks.register("publishAllMavens") {
     dependsOn(":forge:publishToMavenLocal")
     dependsOn(":forge:kfflib:publishToMavenLocal")
     dependsOn(":forge:kfflang:publishToMavenLocal")
     dependsOn(":forge:kffmod:publishToMavenLocal")
-}
\ No newline at end of file
+}
diff --git a/forge/kfflang/build.gradle.kts b/forge/kfflang/build.gradle.kts
index 3bf66e7f..347681f6 100644
--- a/forge/kfflang/build.gradle.kts
+++ b/forge/kfflang/build.gradle.kts
@@ -1,3 +1,4 @@
+import net.minecraftforge.gradle.common.util.RunConfig
 import java.time.LocalDateTime
 
 plugins {
@@ -12,7 +13,7 @@ minecraft {
     copyIdeResources.set(true)
 
     runs {
-        create("client") {
+        create("client", Action<RunConfig> {
             workingDirectory(project.file("run"))
 
             ideaModule = "KotlinForForge.forge.kfflang.test"
@@ -29,7 +30,7 @@ minecraft {
                     source(sourceSets.test.get())
                 }
             }
-        }
+        })
 
         create("server") {
             workingDirectory(project.file("run/server"))
diff --git a/forge/kfflib/build.gradle.kts b/forge/kfflib/build.gradle.kts
index 10999341..d0ae7d83 100644
--- a/forge/kfflib/build.gradle.kts
+++ b/forge/kfflib/build.gradle.kts
@@ -1,4 +1,3 @@
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import java.time.LocalDateTime
 
 plugins {
@@ -118,10 +117,12 @@ tasks {
             )
         }
     }
+}
 
-    // Only require the lang provider to use explicit visibility modifiers, not the test mod
-    withType<KotlinCompile> {
-        kotlinOptions.freeCompilerArgs = listOf("-Xexplicit-api=warning", "-Xjvm-default=all")
+kotlin {
+    compilerOptions {
+        // Only require the lang provider to use explicit visibility modifiers, not the test mod
+        freeCompilerArgs = listOf("-Xexplicit-api=warning", "-Xjvm-default=all")
     }
 }
 
diff --git a/forge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt b/forge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt
index 30992c2c..5ff91bbd 100644
--- a/forge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt
+++ b/forge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt
@@ -4,13 +4,13 @@ import net.minecraft.gametest.framework.GameTest
 import net.minecraft.gametest.framework.GameTestAssertException
 import net.minecraft.gametest.framework.GameTestHelper
 import net.minecraft.resources.ResourceLocation
+import net.minecraftforge.gametest.GameTestDontPrefix
 import net.minecraftforge.gametest.GameTestHolder
-import net.minecraftforge.gametest.PrefixGameTestTemplate
 import net.minecraftforge.registries.ForgeRegistries
 
 @GameTestHolder(KFFLibTest.ID)
 public object InGameTester {
-    @PrefixGameTestTemplate(false)
+    @GameTestDontPrefix
     @GameTest(template = "dummy")
     @JvmStatic
     public fun testBlock(helper: GameTestHelper) {
@@ -20,4 +20,4 @@ public object InGameTester {
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/gradle.properties b/gradle.properties
index 4a83c9d8..86680f83 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -15,4 +15,4 @@ forge_version=49.0.8
 min_neo_version = 20.2.3-beta
 neo_version = 20.4.22-beta
 
-kff_version=4.11.0
+kff_version=4.12.0
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index fd6f914a..33e4098c 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,7 +1,8 @@
 [versions]
-kotlin = "2.0.0"
-coroutines = "1.8.1"
-serialization = "1.6.3"
+jba = "23.0.0"
+kotlin = "2.2.10"
+coroutines = "1.10.2"
+serialization = "1.9.0"
 neogradle = "7.0.138"
 neoforge = "20.4.22-beta"
 forgegradle = "6.0.25"
@@ -28,4 +29,4 @@ kotlinJvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 neogradle = { id = "net.neoforged.gradle.userdev", version.ref = "neogradle" }
 forgegradle = { id = "net.minecraftforge.gradle", version.ref = "forgegradle" }
 minotaur = { id = "com.modrinth.minotaur", version.ref = "minotaur" }
-cursegradle = { id = "com.matthewprenger.cursegradle", version.ref = "cursegradle" }
\ No newline at end of file
+cursegradle = { id = "com.matthewprenger.cursegradle", version.ref = "cursegradle" }
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 7454180f..e6441136 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 20db9ad5..ca025c83 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.14-bin.zip
 networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
diff --git a/gradlew b/gradlew
index 1b6c7873..b740cf13 100755
--- a/gradlew
+++ b/gradlew
@@ -55,7 +55,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,13 +80,11 @@ do
     esac
 done
 
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-APP_NAME="Gradle"
+# This is normally unused
+# shellcheck disable=SC2034
 APP_BASE_NAME=${0##*/}
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -133,22 +131,29 @@ location of your Java installation."
     fi
 else
     JAVACMD=java
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -193,11 +198,15 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
@@ -205,6 +214,12 @@ set -- \
         org.gradle.wrapper.GradleWrapperMain \
         "$@"
 
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
 # Use "xargs" to parse quoted args.
 #
 # With -n1 it outputs one arg per line, with the quotes and backslashes removed.
diff --git a/gradlew.bat b/gradlew.bat
index 107acd32..25da30db 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -14,7 +14,7 @@
 @rem limitations under the License.
 @rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +25,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,13 +41,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,11 +57,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -75,13 +76,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal
diff --git a/neoforge/build.gradle.kts b/neoforge/build.gradle.kts
index 64700510..344aea49 100644
--- a/neoforge/build.gradle.kts
+++ b/neoforge/build.gradle.kts
@@ -58,7 +58,7 @@ fun DependencyHandler.include(dep: ModuleDependency): ModuleDependency {
 }
 
 // maven.repo.local is set within the Julia script in the website branch
-tasks.create("publishAllMavens") {
+tasks.register("publishAllMavens") {
     dependsOn(":neoforge:publishToMavenLocal")
     dependsOn(":neoforge:kfflib:publishToMavenLocal")
     dependsOn(":neoforge:kfflang:publishToMavenLocal")
diff --git a/neoforge/kfflang/build.gradle.kts b/neoforge/kfflang/build.gradle.kts
index 35f3f666..cef02f55 100644
--- a/neoforge/kfflang/build.gradle.kts
+++ b/neoforge/kfflang/build.gradle.kts
@@ -1,5 +1,4 @@
 import net.neoforged.gradle.dsl.common.extensions.RunnableSourceSet
-import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import java.time.LocalDateTime
 
 plugins {
@@ -9,14 +8,20 @@ plugins {
 // Tells NeoGradle to treat this source set as a separate mod
 sourceSets["test"].extensions.getByType<RunnableSourceSet>().configure { run -> run.modIdentifier("kfflangtest") }
 
-val nonmclibs: Configuration by configurations.creating {}
+val nonmclibs: Configuration by configurations.creating {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.jetbrains" && requested.name == "annotations") {
+            useVersion(libs.versions.jba.get())
+            because("JPMS automatic module name")
+        }
+    }
+}
 
 runs {
     configureEach {
-        modSource(sourceSets["main"])
-        //modSource(sourceSets["test"])
+        modSource(sourceSets["test"])
         dependencies {
-            runtime((nonmclibs))
+            runtime.add(nonmclibs)
         }
     }
     create("client")
@@ -54,10 +59,12 @@ tasks {
             )
         }
     }
+}
 
-    // Only require the lang provider to use explicit visibility modifiers, not the test mod
-    withType<KotlinCompile> {
-        kotlinOptions.freeCompilerArgs = listOf("-Xexplicit-api=warning", "-Xjvm-default=all")
+kotlin {
+    compilerOptions {
+        // Only require the lang provider to use explicit visibility modifiers, not the test mod
+        freeCompilerArgs = listOf("-Xexplicit-api=warning", "-Xjvm-default=all")
     }
 }
 
diff --git a/neoforge/kfflang/src/test/kotlin/thedarkcolour/kotlinforforgetest/KFFLangTest.kt b/neoforge/kfflang/src/test/kotlin/thedarkcolour/kotlinforforgetest/KFFLangTest.kt
index acd0aaa2..a4b320e8 100644
--- a/neoforge/kfflang/src/test/kotlin/thedarkcolour/kotlinforforgetest/KFFLangTest.kt
+++ b/neoforge/kfflang/src/test/kotlin/thedarkcolour/kotlinforforgetest/KFFLangTest.kt
@@ -16,12 +16,12 @@ import org.apache.logging.log4j.Logger
  * check out the [KotlinModdingSkeleton repository](https://github.com/thedarkcolour/KotlinModdingSkeleton).
  */
 @Mod(KFFLangTest.ID)
-object KFFLangTest {
-    const val ID = "kfflangtest"
+public object KFFLangTest {
+    public const val ID: String = "kfflangtest"
 
-    val LOGGER: Logger = LogManager.getLogger(ID)
+    private val LOGGER: Logger = LogManager.getLogger(ID)
 
     init {
         LOGGER.log(Level.INFO, "Hello world from Kotlin for forge Language provider!")
     }
-}
\ No newline at end of file
+}
diff --git a/neoforge/kfflib/build.gradle.kts b/neoforge/kfflib/build.gradle.kts
index 41fa4e14..89b2ee07 100644
--- a/neoforge/kfflib/build.gradle.kts
+++ b/neoforge/kfflib/build.gradle.kts
@@ -4,6 +4,23 @@ plugins {
     id("kff.neoforge-conventions")
 }
 
+val nonmclibs: Configuration by configurations.creating {
+    resolutionStrategy.eachDependency {
+        if (requested.group == "org.jetbrains" && requested.name == "annotations") {
+            useVersion(libs.versions.jba.get())
+            because("JPMS automatic module name")
+        }
+    }
+}
+
+val gameTestServer by runs.creating {
+    systemProperty("neoforge.enabledGameTestNamespaces", "kfflibtest")
+    modSources(sourceSets["test"])
+    dependencies {
+        runtime.add(nonmclibs)
+    }
+}
+
 dependencies {
     implementation("net.neoforged:neoforge:${project.properties["neo_version"]}")
 
@@ -15,6 +32,15 @@ dependencies {
     api(libs.kotlinx.coroutines.jdk8)
     api(libs.kotlinx.serialization.json)
 
+    nonmclibs(libs.kotlin.stdlib)
+    nonmclibs(libs.kotlin.stdlib.jdk8)
+    nonmclibs(libs.kotlin.stdlib.jdk7)
+    nonmclibs(libs.kotlin.reflect)
+    nonmclibs(libs.kotlinx.coroutines.core)
+    nonmclibs(libs.kotlinx.coroutines.core.jvm)
+    nonmclibs(libs.kotlinx.coroutines.jdk8)
+    nonmclibs(libs.kotlinx.serialization.json)
+
     implementation(projects.neoforge.kfflang)
 }
 
diff --git a/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt
new file mode 100644
index 00000000..57d56a6c
--- /dev/null
+++ b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/InGameTester.kt
@@ -0,0 +1,23 @@
+package thedarkcolour.kfflibtest
+
+import net.minecraft.core.registries.BuiltInRegistries
+import net.minecraft.gametest.framework.GameTest
+import net.minecraft.gametest.framework.GameTestAssertException
+import net.minecraft.gametest.framework.GameTestHelper
+import net.minecraft.resources.ResourceLocation
+import net.neoforged.neoforge.gametest.GameTestHolder
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate
+
+@GameTestHolder(KFFLibTest.ID)
+public object InGameTester {
+    @PrefixGameTestTemplate(false)
+    @GameTest(template = "dummy")
+    @JvmStatic
+    public fun testBlock(helper: GameTestHelper) {
+        helper.succeedIf {
+            if (!BuiltInRegistries.BLOCK.containsKey(ResourceLocation(KFFLibTest.ID, "example_block"))) {
+                throw GameTestAssertException("Block is not registered correctly!")
+            }
+        }
+    }
+}
diff --git a/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/KFFLibTest.kt b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/KFFLibTest.kt
new file mode 100644
index 00000000..feb8018e
--- /dev/null
+++ b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/KFFLibTest.kt
@@ -0,0 +1,40 @@
+package thedarkcolour.kfflibtest
+
+import net.neoforged.fml.common.Mod
+import org.apache.logging.log4j.Level
+import org.apache.logging.log4j.LogManager
+import org.apache.logging.log4j.Logger
+import thedarkcolour.kotlinforforge.neoforge.forge.MOD_BUS
+
+/**
+ * Set `modLoader` in mods.toml to
+ * `"kotlinforforge"` and loaderVersion to `"[3,)"`.
+ *
+ * Make sure to use [MOD_CONTEXT]
+ * instead of [FMLJavaModLoadingContext].
+ *
+ * For a more detailed example mod,
+ * check out the [KotlinModdingSkeleton repository](https://github.com/thedarkcolour/KotlinModdingSkeleton).
+ */
+@Mod(KFFLibTest.ID)
+public object KFFLibTest {
+    internal const val ID = "kfflibtest"
+
+    internal val LOGGER: Logger = LogManager.getLogger(ID)
+
+    init {
+        LOGGER.log(Level.INFO, "Hello world!")
+
+        ModBlocks.REGISTRY.register(MOD_BUS)
+
+        repeat(30) {
+            testVec2()
+            testVec3i()
+            testVec3()
+            testVector3d()
+            testVector3f()
+            testVector4f()
+            testVector4d()
+        }
+    }
+}
diff --git a/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/ModBlocks.kt b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/ModBlocks.kt
new file mode 100644
index 00000000..f30ebfc3
--- /dev/null
+++ b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/ModBlocks.kt
@@ -0,0 +1,17 @@
+package thedarkcolour.kfflibtest
+
+import net.minecraft.core.registries.BuiltInRegistries
+import net.minecraft.world.level.block.Block
+import net.minecraft.world.level.block.state.BlockBehaviour
+import net.minecraft.world.level.material.MapColor
+import net.neoforged.neoforge.registries.DeferredRegister
+import thedarkcolour.kotlinforforge.neoforge.forge.getValue
+import java.util.function.Supplier
+
+internal object ModBlocks {
+    internal val REGISTRY = DeferredRegister.create(BuiltInRegistries.BLOCK, KFFLibTest.ID)
+
+    internal val EXAMPLE_BLOCK by REGISTRY.register("example_block", Supplier {
+        Block(BlockBehaviour.Properties.of().mapColor(MapColor.PLANT).strength(4.0f))
+    })
+}
diff --git a/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/VectorTester.kt b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/VectorTester.kt
new file mode 100644
index 00000000..a41abd2e
--- /dev/null
+++ b/neoforge/kfflib/src/test/kotlin/thedarkcolour/kfflibtest/VectorTester.kt
@@ -0,0 +1,510 @@
+package thedarkcolour.kfflibtest
+
+import net.minecraft.core.Vec3i
+import net.minecraft.util.Mth
+import net.minecraft.world.phys.Vec2
+import net.minecraft.world.phys.Vec3
+import org.joml.*
+import thedarkcolour.kotlinforforge.neoforge.forge.vectorutil.v2d.*
+import thedarkcolour.kotlinforforge.neoforge.forge.vectorutil.v3d.*
+import thedarkcolour.kotlinforforge.neoforge.forge.vectorutil.v4d.*
+import kotlin.IllegalStateException
+import kotlin.random.Random
+import kotlin.random.nextInt
+
+internal fun testVec2() {
+    val x1 = nextFloat()
+    val y1 = nextFloat()
+
+    val x2 = nextFloat()
+    val y2 = nextFloat()
+
+    val v1 = Vec2(x1, y1)
+    val v2 = Vec2(x2, y2)
+
+    val (a, b) = v1
+    requireEquality(a, x1) { "Vec2 deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vec2 deconstruction for y has failed!" }
+
+    requireEquality(x1, v1[0]) { "Vec2 index access for x has failed! "}
+    requireEquality(y1, v1[1]) { "Vec2 index access for y has failed! "}
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vec2 iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vec2 iterator y has failed! "}
+        }
+        if (index >= 2) {
+            throw IllegalStateException("Vec2 has no 3rd element!")
+        }
+    }
+
+    // I can't believe Vec2#equals does not override Object#equals
+    // It's entirely separate method with same name
+    requireEquality(v1 + v2, Vec2(x1 + x2, y1 + y2), Vec2::equals) { "Vec2 addition has failed!" }
+    requireEquality(v1 - v2, Vec2(x1 - x2, y1 - y2), Vec2::equals) { "Vec2 subtraction has failed!" }
+    requireEquality(-v1, Vec2(-x1, -y1), Vec2::equals) { "Vec2 unaryMinus has failed!" }
+
+    val scalar = nextFloat()
+    requireEquality(v1 * scalar, Vec2(x1 * scalar, y1 * scalar), Vec2::equals) { "Vec2 scalar multiplication has failed! " }
+    requireEquality(v1 * v2, Vec2(x1 * x2, y1 * y2), Vec2::equals) { "Vec2 * Vec2 multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vec2(x1 / scalar, y1 / scalar), Vec2::equals) { "Vec2 scalar division has failed! " }
+    requireEquality(v1 / v2, Vec2(x1 / x2, y1 / y2), Vec2::equals) { "Vec2 / Vec2 division has failed! " }
+
+    requireEquality(v1.deepCopy(), v1, Vec2::equals) { "Vec2 cloning has failed! " }
+
+    requireEquality(v1, Vec2(x1, y1), Vec2::equals) { "v1 has been mutated!" }
+    requireEquality(v2, Vec2(x2, y2), Vec2::equals) { "v2 has been mutated!" }
+}
+
+internal fun testVec3i() {
+    val (x1, y1, z1) = listOf(nextInt(), nextInt(), nextInt())
+    val (x2, y2, z2) = listOf(nextInt(), nextInt(), nextInt())
+
+    val v1 = Vec3i(x1, y1, z1)
+    val v2 = Vec3i(x2, y2, z2)
+
+    val (a, b, c) = v1
+
+    requireEquality(a, x1) { "Vec3i deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vec3i deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vec3i deconstruction for z has failed!" }
+
+    requireEquality(v1[0], x1) { "Vec3i index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vec3i index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vec3i index access for z has failed!" }
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vec3i iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vec3i iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vec3i iterator z has failed! "}
+        }
+        if (index >= 3) {
+            throw IllegalStateException("Vec3i has no 4th element!")
+        }
+    }
+
+    requireEquality(v1 + v2, Vec3i(x1 + x2, y1 + y2, z1 + z2)) { "Vec3i addition has failed!" }
+    requireEquality(v1 - v2, Vec3i(x1 - x2, y1 - y2, z1 - z2)) { "Vec3i subtraction has failed!" }
+    requireEquality(-v1, Vec3i(-x1, -y1, -z1)) { "Vec3i unaryMinus has failed!" }
+
+    val scalar = nextInt()
+    requireEquality(v1 * scalar, Vec3i(x1 * scalar, y1 * scalar, z1 * scalar)) { "Vec3i scalar multiplication has failed! " }
+    requireEquality(v1 * v2, Vec3i(x1 * x2, y1 * y2, z1 * z2)) { "Vec3i * Vec3i multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vec3i(x1 / scalar, y1 / scalar, z1 / scalar)) { "Vec3i scalar division has failed! " }
+    requireEquality(v1 / v2, Vec3i(x1 / x2, y1 / y2, z1 / z2)) { "Vec3i / Vec3i division has failed! " }
+
+    requireEquality(v1.deepCopy(), Vec3i(x1, y1, z1)) { "Vec3i cloning has failed! " }
+
+    requireEquality(v1, Vec3i(x1, y1, z1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vec3i(x2, y2, z2)) { "v2 has been mutated!" }
+
+    val vec3 = Vec3(x1.toDouble(), y1.toDouble(), z1.toDouble())
+    val vector3f = Vector3f(x1.toFloat(), y1.toFloat(), z1.toFloat())
+    val vector3d = Vector3d(x1.toDouble(), y1.toDouble(), z1.toDouble())
+
+    requireEquality(v1, vec3.toVec3i()) { "Vec3 -> Vec3i conversion has failed!" }
+    requireEquality(v1, vector3f.toVec3i()) { "Vector3f -> Vec3i conversion has failed!" }
+    requireEquality(v1, vector3d.toVec3i()) { "Vector3d -> Vec3i conversion has failed!" }
+}
+
+internal fun testVec3() {
+    val (x1, y1, z1) = listOf(nextDouble(), nextDouble(), nextDouble())
+    val (x2, y2, z2) = listOf(nextDouble(), nextDouble(), nextDouble())
+
+    val v1 = Vec3(x1, y1, z1)
+    val v2 = Vec3(x2, y2, z2)
+
+    val (a, b, c) = v1
+
+    requireEquality(a, x1) { "Vec3 deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vec3 deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vec3 deconstruction for z has failed!" }
+
+    requireEquality(v1[0], x1) { "Vec3 index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vec3 index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vec3 index access for z has failed!" }
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vec3 iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vec3 iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vec3 iterator z has failed! "}
+        }
+        if (index >= 3) {
+            throw IllegalStateException("Vec3 has no 4th element!")
+        }
+    }
+
+    requireEquality(v1 + v2, Vec3(x1 + x2, y1 + y2, z1 + z2)) { "Vec3 addition has failed!" }
+    requireEquality(v1 - v2, Vec3(x1 - x2, y1 - y2, z1 - z2)) { "Vec3 subtraction has failed!" }
+    requireEquality(-v1, Vec3(-x1, -y1, -z1)) { "Vec3 unaryMinus has failed!" }
+
+    val scalar = nextDouble()
+    requireEquality(v1 * scalar, Vec3(x1 * scalar, y1 * scalar, z1 * scalar)) { "Vec3 multiplication has failed! " }
+    requireEquality(v1 * v2, Vec3(x1 * x2, y1 * y2, z1 * z2)) { "Vec3 multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vec3(x1 / scalar, y1 / scalar, z1 / scalar)) { "Vec3 scalar division has failed! " }
+    requireEquality(v1 / v2, Vec3(x1 / x2, y1 / y2, z1 / z2)) { "Vec3 / Vec3 division has failed! " }
+
+    requireEquality(v1.deepCopy(), v1) { "Vec3 cloning has failed! " }
+
+    requireEquality(v1, Vec3(x1, y1, z1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vec3(x2, y2, z2)) { "v2 has been mutated!" }
+
+    val vec3i = Vec3i(Mth.floor(x1), Mth.floor(y1), Mth.floor(z1))
+    val vector3f = Vector3f(x1.toFloat(), y1.toFloat(), z1.toFloat())
+    val vector3d = Vector3d(x1, y1, z1)
+
+    requireEquality(v1, vec3i.toVec3()) { "Vec3i -> Vec3 conversion has failed!" }
+    requireEquality(v1, vector3f.toVec3()) { "Vector3f -> Vec3 conversion has failed!" }
+    requireEquality(v1, vector3d.toVec3()) { "Vector3d -> Vec3 conversion has failed!" }
+}
+
+internal fun testVector3d() {
+    val (x1, y1, z1) = listOf(nextDouble(), nextDouble(), nextDouble())
+    val (x2, y2, z2) = listOf(nextDouble(), nextDouble(), nextDouble())
+    val tester: (Vector3dc, Vector3dc) -> Boolean = { a, b ->
+        a == b || a.distanceSquared(b) < 0.01
+    }
+
+    val v1: Vector3dc = Vector3d(x1, y1, z1)
+    val v2: Vector3dc = Vector3d(x2, y2, z2)
+
+    val (a, b, c) = v1
+
+    requireEquality(a, x1) { "Vector3d deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vector3d deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vector3d deconstruction for z has failed!" }
+
+    requireEquality(v1[0], x1) { "Vector3d index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vector3d index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vector3d index access for z has failed!" }
+
+    val v3 = Vector3d()
+    
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vector3d iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vector3d iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vector3d iterator z has failed! "}
+        }
+        if (index >= 3) {
+            throw IllegalStateException("Vector3d has no 4th element!")
+        }
+        v3[index] = element
+    }
+    
+    requireEquality(v1, v3) { "Vector3d index setter has failed! "}
+
+    requireEquality(v1 + v2,  Vector3d(x1 + x2, y1 + y2, z1 + z2)) { "Vector3d addition has failed!" }
+    requireEquality(v1 - v2, Vector3d(x1 - x2, y1 - y2, z1 - z2)) { "Vector3d subtraction has failed!" }
+    requireEquality(-v1, Vector3d(-x1, -y1, -z1)) { "Vector3d unaryMinus has failed!" }
+
+    val scalar = nextDouble()
+    requireEquality(v1 * scalar, Vector3d(x1 * scalar, y1 * scalar, z1 * scalar), tester) { "Vector3d scalar multiplication has failed! " }
+    requireEquality(v1 * v2, Vector3d(x1 * x2, y1 * y2, z1 * z2), tester) { "Vector3d * Vector3d multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vector3d(x1 / scalar, y1 / scalar, z1 / scalar), tester) { "Vector3d scalar division has failed! " }
+    requireEquality(v1 / v2, Vector3d(x1 / x2, y1 / y2, z1 / z2), tester) { "Vector3d / Vector3d division has failed! " }
+
+    requireEquality(v1.deepCopy(), v1) { "Vector3d cloning has failed!" }
+
+    val plusAssign = v1.deepCopy()
+    plusAssign += v2
+    requireEquality(v1 + v2, plusAssign) { "Vector3d addition&assign has failed!" }
+
+    val minusAssign = v1.deepCopy()
+    minusAssign -= v2
+    requireEquality(v1 - v2, minusAssign) { "Vector3d subtraction&assign has failed!" }
+
+    val timesAssign = v1.deepCopy()
+    timesAssign *= scalar
+    requireEquality(v1 * scalar, timesAssign) { "Vector3d multiplication&assign has failed!" }
+
+    val divAssign = v1.deepCopy()
+    divAssign /= scalar
+    requireEquality(v1 / scalar, divAssign) { "Vector3d division&assign has failed!" }
+
+    requireEquality(v1, Vector3d(x1, y1, z1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vector3d(x2, y2, z2)) { "v2 has been mutated!" }
+
+    val vec3i = Vec3i(Mth.floor(x1), Mth.floor(y1), Mth.floor(z1))
+    val vector3f = Vector3f(x1.toFloat(), y1.toFloat(), z1.toFloat())
+    val vec3 = Vec3(x1, y1, z1)
+
+    requireEquality(v1, vec3i.toVector3d()) { "Vec3i -> Vector3d conversion has failed!" }
+    requireEquality(v1, vector3f.toVector3d()) { "Vector3f -> Vector3d conversion has failed!" }
+    requireEquality(v1, vec3.toVector3d()) { "Vec3 -> Vector3d conversion has failed!" }
+
+    KFFLibTest.LOGGER.info("Vector3d test succeed")
+}
+
+internal fun testVector3f() {
+    val (x1, y1, z1) = listOf(nextFloat(), nextFloat(), nextFloat())
+    val (x2, y2, z2) = listOf(nextFloat(), nextFloat(), nextFloat())
+    val tester: (Vector3fc, Vector3fc) -> Boolean = { a, b ->
+        a == b || a.distanceSquared(b) < 0.01
+    }
+
+    val v1: Vector3fc = Vector3f(x1, y1, z1)
+    val v2: Vector3fc = Vector3f(x2, y2, z2)
+
+    val (a, b, c) = v1
+
+    requireEquality(a, x1) { "Vector3f deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vector3f deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vector3f deconstruction for z has failed!" }
+
+    requireEquality(v1[0], x1) { "Vector3f index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vector3f index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vector3f index access for z has failed!" }
+
+    val v3 = Vector3f()
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vector3f iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vector3f iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vector3f iterator z has failed! "}
+        }
+        if (index >= 3) {
+            throw IllegalStateException("Vector3f has no 4th element!")
+        }
+        v3[index] = element
+    }
+
+    requireEquality(v1, v3) { "Vector3f index setter has failed! "}
+    
+    requireEquality(v1 + v2, Vector3f(x1 + x2, y1 + y2, z1 + z2)) { "Vector3f addition has failed!" }
+    requireEquality(v1 - v2, Vector3f(x1 - x2, y1 - y2, z1 - z2)) { "Vector3f subtraction has failed!" }
+    requireEquality(-v1, Vector3f(-x1, -y1, -z1)) { "Vector3f unaryMinus has failed!" }
+
+    val scalar = nextFloat()
+    requireEquality(v1 * scalar, Vector3f(x1 * scalar, y1 * scalar, z1 * scalar), tester) { "Vector3f multiplication has failed! " }
+    requireEquality(v1 * v2, Vector3f(x1 * x2, y1 * y2, z1 * z2), tester) { "Vector3f * Vector3f multiplication has failed! " }
+    requireEquality(v1.deepCopy(), v1) { "Vector3f cloning has failed! " }
+
+    requireEquality(v1 / scalar, Vector3f(x1 / scalar, y1 / scalar, z1 / scalar), tester) { "Vector3f scalar division has failed! " }
+    requireEquality(v1 / v2, Vector3f(x1 / x2, y1 / y2, z1 / z2), tester) { "Vector3f / Vector3f division has failed! " }
+    
+    val plusAssign = v1.deepCopy()
+    plusAssign += v2
+    requireEquality(v1 + v2, plusAssign) { "Vector3f addition&assign has failed!" }
+
+    val minusAssign = v1.deepCopy()
+    minusAssign -= v2
+    requireEquality(v1 - v2, minusAssign) { "Vector3f subtraction&assign has failed!" }
+
+    val timesAssign = v1.deepCopy()
+    timesAssign *= scalar
+    requireEquality(v1 * scalar, timesAssign) { "Vector3f multiplication&assign has failed!" }
+
+    val divAssign = v1.deepCopy()
+    divAssign /= scalar
+    requireEquality(v1 / scalar, divAssign) { "Vector3f division&assign has failed!" }
+
+    requireEquality(v1, Vector3f(x1, y1 ,z1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vector3f(x2, y2, z2)) { "v2 has been mutated!" }
+
+    val vec3i = Vec3i(x1.toInt(), y1.toInt(), z1.toInt())
+    val vector3d = Vector3d(x1.toDouble(), y1.toDouble(), z1.toDouble())
+    val vec3 = Vec3(x1.toDouble(), y1.toDouble(), z1.toDouble())
+
+    requireEquality(v1, vec3i.toVector3f()) { "Vec3i -> Vector3f conversion has failed!" }
+    requireEquality(v1, vector3d.toVector3f()) { "Vector3f -> Vector3f conversion has failed!" }
+    requireEquality(v1, vec3.toVector3f()) { "Vec3 -> Vector3f conversion has failed!" }
+}
+
+internal fun testVector4f() {
+    val (x1, y1, z1, w1) = listOf(nextFloat(), nextFloat(), nextFloat(), nextFloat())
+    val (x2, y2, z2, w2) = listOf(nextFloat(), nextFloat(), nextFloat(), nextFloat())
+    val tester: (Vector4fc, Vector4fc) -> Boolean = { a: Vector4fc, b: Vector4fc ->
+        a == b || a.distanceSquared(b) < 0.01
+    }
+
+    val v1: Vector4fc = Vector4f(x1, y1, z1, w1)
+    val v2: Vector4fc = Vector4f(x2, y2, z2, w2)
+
+    val (a, b, c, d) = v1
+
+    requireEquality(a, x1) { "Vector4f deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vector4f deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vector4f deconstruction for z has failed!" }
+    requireEquality(d, w1) { "Vector4f deconstruction for w has failed!" }
+
+    requireEquality(v1[0], x1) { "Vector4f index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vector4f index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vector4f index access for z has failed!" }
+    requireEquality(v1[3], w1) { "Vector4f index access for z has failed!" }
+
+    val v3 = Vector4f()
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vector4f iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vector4f iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vector4f iterator z has failed! "}
+        }
+        if (index == 3) {
+            requireEquality(w1, element) { "Vector4f iterator w has failed! "}
+        }
+        if (index >= 4) {
+            throw IllegalStateException("Vector4f has no 5th element!")
+        }
+        v3[index] = element
+    }
+
+    requireEquality(v1, v3) { "Vector4f index setter has failed! "}
+    
+    requireEquality(v1 + v2, Vector4f(x1 + x2, y1 + y2, z1 + z2, w1 + w2)) { "Vector4f addition has failed!" }
+    requireEquality(v1 - v2, Vector4f(x1 - x2, y1 - y2, z1 - z2, w1 - w2)) { "Vector4f subtraction has failed!" }
+    requireEquality(-v1, Vector4f(-x1, -y1, -z1, -w1)) { "Vector4f unaryMinus has failed!" }
+
+    val scalar = nextFloat()
+    requireEquality(v1 * scalar, Vector4f(x1 * scalar, y1 * scalar, z1 * scalar, w1 * scalar), tester) { "Vector4f scala multiplication has failed! " }
+    requireEquality(v1 * v2, Vector4f(x1 * x2, y1 * y2, z1 * z2, w1 * w2), tester) { "Vector4f * Vector4f multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vector4f(x1 / scalar, y1 / scalar, z1 / scalar, w1 / scalar), tester) { "Vector4f scala division has failed! " }
+    requireEquality(v1 / v2, Vector4f(x1 / x2, y1 / y2, z1 / z2, w1 / w2), tester) { "Vector4f / Vector4f division has failed! " }
+    
+    requireEquality(v1.deepCopy(), v1) { "Vector4f cloning has failed! " }
+
+    requireEquality(v1, Vector4f(x1, y1, z1, w1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vector4f(x2, y2, z2, w2)) { "v2 has been mutated!" }
+
+    val plusAssign = v1.deepCopy()
+    plusAssign += v2
+    requireEquality(v1 + v2, plusAssign) { "Vector4f addition&assign has failed!" }
+
+    val minusAssign = v1.deepCopy()
+    minusAssign -= v2
+    requireEquality(v1 - v2, minusAssign) { "Vector4f subtraction&assign has failed!" }
+
+    val timesAssign = v1.deepCopy()
+    timesAssign *= scalar
+    requireEquality(v1 * scalar, timesAssign) { "Vector4f multiplication&assign has failed!" }
+
+    val divAssign = v1.deepCopy()
+    divAssign /= scalar
+    requireEquality(v1 / scalar, divAssign) { "Vector4f division&assign has failed!" }
+
+    KFFLibTest.LOGGER.info("Vector4f test succeed")
+}
+
+internal fun testVector4d() {
+    val (x1, y1, z1, w1) = listOf(nextDouble(), nextDouble(), nextDouble(), nextDouble())
+    val (x2, y2, z2, w2) = listOf(nextDouble(), nextDouble(), nextDouble(), nextDouble())
+    val tester: (Vector4dc, Vector4dc) -> Boolean = { a, b ->
+        a == b || a.distanceSquared(b) < 0.01
+    }
+
+    val v1: Vector4dc = Vector4d(x1, y1, z1, w1)
+    val v2: Vector4dc = Vector4d(x2, y2, z2, w2)
+
+    val (a, b, c, d) = v1
+
+    requireEquality(a, x1) { "Vector4d deconstruction for x has failed!" }
+    requireEquality(b, y1) { "Vector4d deconstruction for y has failed!" }
+    requireEquality(c, z1) { "Vector4d deconstruction for z has failed!" }
+    requireEquality(d, w1) { "Vector4d deconstruction for w has failed!" }
+
+    requireEquality(v1[0], x1) { "Vector4d index access for x has failed!" }
+    requireEquality(v1[1], y1) { "Vector4d index access for y has failed!" }
+    requireEquality(v1[2], z1) { "Vector4d index access for z has failed!" }
+    requireEquality(v1[3], w1) { "Vector4d index access for z has failed!" }
+
+    val v3 = Vector4d()
+
+    for ((index, element) in v1.iterator().withIndex()) {
+        if (index == 0) {
+            requireEquality(x1, element) { "Vector4d iterator x has failed! "}
+        }
+        if (index == 1) {
+            requireEquality(y1, element) { "Vector4d iterator y has failed! "}
+        }
+        if (index == 2) {
+            requireEquality(z1, element) { "Vector4d iterator z has failed! "}
+        }
+        if (index == 3) {
+            requireEquality(w1, element) { "Vector4d iterator w has failed! "}
+        }
+        if (index >= 4) {
+            throw IllegalStateException("Vector4d has no 5th element!")
+        }
+        v3[index] = element
+    }
+
+    requireEquality(v1, v3) { "Vector4d index setter has failed! "}
+
+    requireEquality(v1 + v2, Vector4d(x1 + x2, y1 + y2, z1 + z2, w1 + w2)) { "Vector4d addition has failed!" }
+    requireEquality(v1 - v2, Vector4d(x1 - x2, y1 - y2, z1 - z2, w1 - w2)) { "Vector4d subtraction has failed!" }
+    requireEquality(-v1, Vector4d(-x1, -y1, -z1, -w1)) { "Vector4d unaryMinus has failed!" }
+
+    val scalar = nextDouble()
+    requireEquality(v1 * scalar, Vector4d(x1 * scalar, y1 * scalar, z1 * scalar, w1 * scalar), tester) { "Vector4d scala multiplication has failed! " }
+    requireEquality(v1 * v2, Vector4d(x1 * x2, y1 * y2, z1 * z2, w1 * w2), tester) { "Vector4d * Vector4d multiplication has failed! " }
+
+    requireEquality(v1 / scalar, Vector4d(x1 / scalar, y1 / scalar, z1 / scalar, w1 / scalar), tester) { "Vector4d scala division has failed! " }
+    requireEquality(v1 / v2, Vector4d(x1 / x2, y1 / y2, z1 / z2, w1 / w2), tester) { "Vector4d / Vector4d division has failed! " }
+
+    requireEquality(v1.deepCopy(), v1) { "Vector4d cloning has failed! " }
+
+    requireEquality(v1, Vector4d(x1, y1, z1, w1)) { "v1 has been mutated!" }
+    requireEquality(v2, Vector4d(x2, y2, z2, w2)) { "v2 has been mutated!" }
+
+    val plusAssign = v1.deepCopy()
+    plusAssign += v2
+    requireEquality(v1 + v2, plusAssign) { "Vector4d addition&assign has failed!" }
+
+    val minusAssign = v1.deepCopy()
+    minusAssign -= v2
+    requireEquality(v1 - v2, minusAssign) { "Vector4d subtraction&assign has failed!" }
+
+    val timesAssign = v1.deepCopy()
+    timesAssign *= scalar
+    requireEquality(v1 * scalar, timesAssign) { "Vector4d multiplication&assign has failed!" }
+
+    val divAssign = v1.deepCopy()
+    divAssign /= scalar
+    requireEquality(v1 / scalar, divAssign) { "Vector4d division&assign has failed!" }
+
+    KFFLibTest.LOGGER.info("Vector4d test succeed")
+}
+
+private fun nextInt() = Random.nextInt(-5000..5000)
+
+private fun nextFloat() = nextInt().toFloat()
+
+private fun nextDouble() = nextInt().toDouble()
+
+private fun <T: Any> requireEquality(a: T, b: T, tester: (T, T) -> Boolean = { f, s -> f == s}, message: () -> String) {
+    if (!tester(a, b)) {
+        throw IllegalStateException("${message()}\nLeft: $a\nRight: $b")
+    }
+}
diff --git a/neoforge/kfflib/src/test/resources/META-INF/mods.toml b/neoforge/kfflib/src/test/resources/META-INF/mods.toml
new file mode 100644
index 00000000..cf03801c
--- /dev/null
+++ b/neoforge/kfflib/src/test/resources/META-INF/mods.toml
@@ -0,0 +1,22 @@
+modLoader="kotlinforforge"
+loaderVersion="[4,)"
+license="LGPL v2.1"
+
+[[mods]]
+displayName="Kotlin for Forge Library Test"
+modId="kfflibtest"
+version="${kff_version}"
+authors="TheDarkColour"
+credits="Herobrine knows all. Thanks to Username404-59 and TheOnlyTails on GitHub"
+issueTrackerURL="https://github.com/thedarkcolour/KotlinForForge/issues"
+description='''
+Kotlin for Forge. Allows mods to use the Kotlin programming language.
+'''
+
+[[dependencies.kotlinforforge]]
+modId="minecraft"
+mandatory=true
+type="required"
+versionRange="[${min_mc_version},${unsupported_mc_version})"
+ordering="NONE"
+side="BOTH"
diff --git a/neoforge/kfflib/src/test/resources/data/kfflibtest/structures/dummy.nbt b/neoforge/kfflib/src/test/resources/data/kfflibtest/structures/dummy.nbt
new file mode 100644
index 00000000..42e2684a
Binary files /dev/null and b/neoforge/kfflib/src/test/resources/data/kfflibtest/structures/dummy.nbt differ
diff --git a/neoforge/kfflib/src/test/resources/pack.mcmeta b/neoforge/kfflib/src/test/resources/pack.mcmeta
new file mode 100644
index 00000000..17e4fa33
--- /dev/null
+++ b/neoforge/kfflib/src/test/resources/pack.mcmeta
@@ -0,0 +1,6 @@
+{
+    "pack": {
+        "description": "Kotlin for Forge Library Test resources",
+        "pack_format": 7
+    }
+}
\ No newline at end of file