Move changelog task to standalone file

buildSrc/src/main/kotlin/com/wbrawner/releasehelper/ChangelogTask.kt

@@ -0,0 +1,39 @@
+package com.wbrawner.releasehelper
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.model.ObjectFactory
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+import javax.inject.Inject
+
+private const val CHANGELOG_PATH = "src/play/play/release-notes/en-US/default.txt"
+
+abstract class ChangelogTask @Inject constructor(objectFactory: ObjectFactory) : DefaultTask() {
+    @get:OutputFile
+    val changelogFile: RegularFileProperty = objectFactory.fileProperty()
+
+    init {
+        changelogFile.set(project.layout.projectDirectory.file(CHANGELOG_PATH))
+    }
+
+    @TaskAction
+    fun execute() {
+        val latestTag = "git describe --tags --abbrev=0".execute()
+        val changelog = "git log --format=\"%B\" ${latestTag.first().trim()}..".execute()
+        logger.info("Latest tag: $latestTag")
+        logger.info("Changelog: ${changelog.joinToString("\n")}")
+        changelogFile.get().asFile.writer().use { writer ->
+            writer.write(
+                changelog.joinToString("\n") { it.trim('"') }
+            )
+        }
+    }
+
+    private fun String.execute(): List<String> = ProcessBuilder()
+        .command(this.split(" "))
+        .redirectOutput(ProcessBuilder.Redirect.PIPE)
+        .start()
+        .inputReader()
+        .readLines()
+}

buildSrc/src/main/kotlin/com/wbrawner/releasehelper/ReleaseHelperPlugin.kt

@@ -2,46 +2,15 @@ package com.wbrawner.releasehelper
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project
-import org.gradle.api.tasks.Exec
 import org.gradle.kotlin.dsl.extra
 import org.gradle.kotlin.dsl.provideDelegate
-import java.io.ByteArrayOutputStream
+import org.gradle.kotlin.dsl.register
 import java.io.File
 
+
 class ReleaseHelperPlugin : Plugin<Project> {
     override fun apply(target: Project) {
-        target.tasks.register("getLatestTag", Exec::class.java) {
-            val latestTag = ByteArrayOutputStream()
-            standardOutput = latestTag
-            commandLine("git describe --tags --abbrev=0".split(" "))
-            doLast {
-                target.project.extra["latestTag"] = latestTag.toString().trim()
-                logger.info("Latest tag: ${target.project.extra["latestTag"]}")
-            }
-        }
-
-        target.tasks.register("changelog") {
-            val changelogFile = File(target.projectDir, "src/play/play/release-notes/en-US/default.txt")
-            inputs.property("tag", target.provider {
-                target.project.extra["latestTag"]
-            })
-            outputs.file(changelogFile)
-            dependsOn("getLatestTag")
-            doLast {
-                val latestTag: String by target.project.extra
-                val changelog = ByteArrayOutputStream()
-                target.exec {
-                    standardOutput = changelog
-                    commandLine = "git log --format=\"%B\" ${latestTag.trim()}..".split(" ")
-                }
-                changelogFile.writeText(
-                        changelog.toString()
-                                .split("\n")
-                                .mapNotNull { it.trim('"').ifBlank { null } }
-                                .joinToString("\n") { "- $it" }
-                )
-            }
-        }
+        target.tasks.register<ChangelogTask>("changelog")
 
         target.tasks.register("majorRelease") {
             dependsOn("changelog", "getLatestTag")