Refactor Manifest Generation into Gradle Plugin

build.gradle.kts

@@ -1,24 +1,18 @@
+import cloud.kubelet.foundation.gradle.FoundationProjectPlugin
+import cloud.kubelet.foundation.gradle.isFoundationPlugin
 import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
-import org.jetbrains.kotlin.com.google.gson.Gson
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
-import java.io.FileWriter
 
 plugins {
   java
   id("cloud.kubelet.foundation.gradle")
 }
 
-fun Project.isFoundationPlugin() = name.startsWith("foundation-")
-fun Project.isFoundationTool() = !isFoundationPlugin()
-
-// Disable the JAR task for the root project.
-tasks["jar"].enabled = false
-
 allprojects {
   repositories {
     mavenCentral()
     maven {
-      name = "papermc-repo"
+      name = "papermc"
       url = uri("https://papermc.io/repo/repository/maven-public/")
     }
 
@@ -29,59 +23,20 @@ allprojects {
   }
 }
 
-val manifestsDir = buildDir.resolve("manifests")
-manifestsDir.mkdirs()
-val gson = Gson()
-
-tasks.create("updateManifests") {
-  // TODO: not using task dependencies, outputs, blah blah blah.
-  doLast {
-    val updateFile = manifestsDir.resolve("update.json")
-    val writer = FileWriter(updateFile)
-    writer.use {
-      val rootPath = rootProject.rootDir.toPath()
-      val updateManifest = subprojects.mapNotNull { project ->
-        if (project.isFoundationTool()) {
-          return@mapNotNull null
-        }
-        val files = project.tasks.getByName("shadowJar").outputs
-        val paths = files.files.map { rootPath.relativize(it.toPath()).toString() }
-
-        if (paths.isNotEmpty()) project.name to mapOf(
-          "version" to project.version,
-          "artifacts" to paths,
-        )
-        else null
-      }.toMap()
-
-      gson.toJson(
-        updateManifest,
-        writer
-      )
-    }
-  }
-}
-
 tasks.assemble {
   dependsOn("updateManifests")
 }
 
+version = "0.2"
+
 subprojects {
   plugins.apply("org.jetbrains.kotlin.jvm")
   plugins.apply("org.jetbrains.kotlin.plugin.serialization")
   plugins.apply("com.github.johnrengelman.shadow")
+  plugins.apply(FoundationProjectPlugin::class)
 
-  version = "0.2"
   group = "io.gorence"
 
-  // Add build number if running under CI.
-  val versionWithBuild = if (System.getenv("CI_PIPELINE_IID") != null) {
-    version as String + ".${System.getenv("CI_PIPELINE_IID")}"
-  } else {
-    "DEV"
-  }
-  version = versionWithBuild
-
   dependencies {
     // Kotlin dependencies
     implementation(platform("org.jetbrains.kotlin:kotlin-bom"))

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/FoundationGlobals.kt

@@ -0,0 +1,7 @@
+package cloud.kubelet.foundation.gradle
+
+import com.google.gson.Gson
+
+object FoundationGlobals {
+  val gson = Gson()
+}

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/FoundationGradlePlugin.kt

@@ -17,5 +17,8 @@ class FoundationGradlePlugin : Plugin<Project> {
     }
     val runPaperServer = project.tasks.create<RunPaperServer>("runPaperServer")
     runPaperServer.dependsOn(setupPaperServer)
+
+    val updateManifests = project.tasks.create<UpdateManifestTask>("updateManifests")
+    project.tasks.getByName("assemble").dependsOn(updateManifests)
   }
 }

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/FoundationProjectPlugin.kt

@@ -0,0 +1,16 @@
+package cloud.kubelet.foundation.gradle
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+
+class FoundationProjectPlugin : Plugin<Project> {
+  override fun apply(project: Project) {
+    val versionWithBuild = if (System.getenv("CI_PIPELINE_IID") != null) {
+      project.rootProject.version.toString() + ".${System.getenv("CI_PIPELINE_IID")}"
+    } else {
+      "DEV"
+    }
+
+    project.version = versionWithBuild
+  }
+}

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/PaperVersionClient.kt

@@ -6,9 +6,11 @@ import java.net.http.HttpClient
 import java.net.http.HttpRequest
 import java.net.http.HttpResponse
 
-class PaperVersionClient(val client: HttpClient = HttpClient.newHttpClient()) {
+class PaperVersionClient(
+  val client: HttpClient = HttpClient.newHttpClient(),
+  private val gson: Gson = FoundationGlobals.gson
+) {
   private val apiBaseUrl = URI.create("https://papermc.io/api/v2/")
-  private val gson = Gson()
 
   fun getVersionBuilds(group: String): List<PaperBuild> {
     val response = client.send(

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/UpdateManifestTask.kt

@@ -0,0 +1,32 @@
+package cloud.kubelet.foundation.gradle
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.tasks.TaskAction
+import java.nio.file.Files
+import java.nio.file.Path
+
+open class UpdateManifestTask : DefaultTask() {
+  @TaskAction
+  fun update() {
+    val manifestsDir = ensureManifestsDir()
+    val updateFile = manifestsDir.resolve("update.json")
+    val rootPath = project.rootProject.rootDir.toPath()
+    val updateManifest = project.findPluginProjects().mapNotNull { project ->
+      val paths = project.shadowJarOutputs.allFilesRelativeToPath(rootPath)
+      if (paths.isNotEmpty()) {
+        project.name to mapOf(
+          "version" to project.version,
+          "artifacts" to paths.map { it.toUnixString() }
+        )
+      } else null
+    }.toMap()
+
+    Files.writeString(updateFile, FoundationGlobals.gson.toJson(updateManifest))
+  }
+
+  private fun ensureManifestsDir(): Path {
+    val manifestsDir = project.buildDir.resolve("manifests")
+    manifestsDir.mkdirs()
+    return manifestsDir.toPath()
+  }
+}

buildSrc/src/main/kotlin/cloud/kubelet/foundation/gradle/extensions.kt

@@ -0,0 +1,17 @@
+package cloud.kubelet.foundation.gradle
+
+import org.gradle.api.Project
+import org.gradle.api.tasks.TaskOutputs
+import java.nio.file.FileSystems
+import java.nio.file.Path
+
+fun Project.isFoundationPlugin() = name.startsWith("foundation-")
+
+fun Project.findPluginProjects() = rootProject.subprojects.filter { project -> project.isFoundationPlugin() }
+
+val Project.shadowJarOutputs: TaskOutputs
+  get() = project.tasks.getByName("shadowJar").outputs
+
+fun TaskOutputs.allFilesRelativeToPath(root: Path): List<Path> = files.map { root.relativize(it.toPath()) }
+
+fun Path.toUnixString() = toString().replace(FileSystems.getDefault().separator, "/")