Auto discover GRAALVM_HOME

buildSrc/src/main/kotlin/native-image.gradle.kts

@@ -1,10 +1,43 @@
+import org.gradle.jvm.toolchain.JavaToolchainService;
+import java.io.ByteArrayOutputStream
+
 task("buildNative") {
     dependsOn("installShadowDist")
 
     outputs.file("${buildDir}/native/scaffold")
 
     doLast {
-        val graalvmHome = System.getenv("GRAALVM_HOME") ?: error("GRAALVM_HOME is not set")
+        val graalvmHome = project.extensions.findByType<JavaToolchainService>()?.launcherFor {
+            languageVersion.set(JavaLanguageVersion.of(19))
+            vendor.set(JvmVendorSpec.GRAAL_VM)
+        }
+            ?.orNull
+            ?.executablePath?.asFile?.toPath()?.parent?.parent?.toString()
+            ?: System.getenv("GRAALVM_HOME")
+            ?: error("GRAALVM_HOME is not set")
+
+        val out = ByteArrayOutputStream()
+
+        exec {
+            commandLine(
+                "${graalvmHome}/bin/gu",
+                "list",
+                "-v",
+            )
+            standardOutput = out
+        }
+
+        val installedComponents = out.toString().lines()
+            .filter { it.startsWith("ID") }
+            .map { it.substringAfter(':').trim() }
+
+        if ("native-image" !in installedComponents) {
+            throw GradleException("GRAALVM: Missing js component")
+        }
+
+        if ("js" !in installedComponents) {
+            throw GradleException("GRAALVM: Missing js component")
+        }
 
         exec {
             commandLine(