[Plan] Migrate Gradle build to Kotlin DSL

[michael-newsrx]

Gradle Kotlin DSL Migration Implementation Plan

For agentic workers: REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (- [ ]) syntax for tracking.

Goal: Migrate Gradle build from Groovy DSL to Kotlin DSL and complete configuration for GitBucket plugin development.

Architecture: Convert existing Gradle files to Kotlin DSL, add Gradle wrapper to version control, and verify build produces fat JAR for GitBucket plugin deployment.

Tech Stack: Gradle 9.3.0, Kotlin DSL, Scala 2.13.18, GradleUp Shadow 8.3.5, Java 21 toolchain / Java 17 target

---

File Structure

Create:

• build.gradle.kts - Build configuration in Kotlin DSL
• settings.gradle.kts - Settings with plugin management in Kotlin DSL

Modify:

• .gitignore - Add !gradle/wrapper/gradle-wrapper.properties entry
• README.md - Clarify build instructions (already has ./gradlew shadowJar)

Delete:

• build.gradle - Old Groovy build file
• settings.gradle - Old Groovy settings file

Track in Git:

• gradlew - Unix executable
• gradlew.bat - Windows script
• gradle/wrapper/gradle-wrapper.jar - Wrapper JAR
• gradle/wrapper/gradle-wrapper.properties - Wrapper config (Gradle 9.3.0)

---

Task 1: Create settings.gradle.kts with Plugin Management

Files:

• Create: settings.gradle.kts

• Step 1: Create settings.gradle.kts

pluginManagement {
    plugins {
        id("scala") version "8.7.0"
        id("com.gradleup.shadow") version "8.3.5"
    }
}

rootProject.name = "gitbucket-mcp-plugin"

• Step 2: Verify settings.gradle.kts syntax

Run: cat settings.gradle.kts
Expected: File contains pluginManagement block and rootProject.name

---

Task 2: Create build.gradle.kts with Complete Configuration

Files:

• Create: build.gradle.kts

• Step 1: Create build.gradle.kts

plugins {
    scala
    id("com.gradleup.shadow")
}

group = "com.newsrx"
version = "0.1.0"

java {
    toolchain {
        languageVersion.set(JavaLanguageVersion.of(21))
    }
}

tasks.withType<JavaCompile>().configureEach {
    sourceCompatibility = "17"
    targetCompatibility = "17"
}

repositories {
    mavenCentral()
    maven { url = uri("https://oss.sonatype.org/content/repositories/releases/") }
}

dependencies {
    implementation("org.scala-lang:scala-library:2.13.18")
    compileOnly("io.github.gitbucket:gitbucket_2.13:4.46.0")
    compileOnly("org.scalatra:scalatra-javax_2.13:3.1.2")
    compileOnly("io.github.json4s:json4s-jackson_2.13:4.1.0")
    compileOnly("javax.servlet:javax.servlet-api:3.1.0")
    
    testImplementation("org.scalatest:scalatest_2.13:3.2.18")
}

scala {
    scalaVersion = "2.13.18"
}

sourceSets {
    main {
        scala {
            setSrcDirs(listOf("src/main/scala", "src/main/java"))
        }
        java {
            setSrcDirs(emptyList<String>())
        }
    }
}

tasks.shadowJar {
    archiveClassifier.set("")
    exclude("META-INF/*.RSA")
    exclude("META-INF/*.SF")
    exclude("META-INF/*.DSA")
}

tasks.build {
    dependsOn(tasks.shadowJar)
}

• Step 2: Verify build.gradle.kts syntax

Run: cat build.gradle.kts
Expected: File contains all plugins, dependencies, and configuration blocks

---

Task 3: Update .gitignore for Gradle Wrapper Properties

Files:

• Modify: .gitignore:4-5

• Step 1: Update .gitignore

The current .gitignore line 4 is:

!gradle/wrapper/gradle-wrapper.jar

Replace with:

!gradle/wrapper/gradle-wrapper.jar
!gradle/wrapper/gradle-wrapper.properties

• Step 2: Verify .gitignore changes

Run: cat .gitignore
Expected: Both gradle-wrapper.jar and gradle-wrapper.properties have exception lines

---

Task 4: Add Gradle Wrapper Files to Git

Files:

• Track: gradlew

• Track: gradlew.bat

• Track: gradle/wrapper/gradle-wrapper.jar

• Track: gradle/wrapper/gradle-wrapper.properties

• Step 1: Stage Gradle wrapper files

git add gradlew gradlew.bat gradle/wrapper/

• Step 2: Verify wrapper files are staged

Run: git status
Expected: All 4 wrapper files show as "new file" or "modified"

---

Task 5: Remove Old Groovy Gradle Files

Files:

• Delete: build.gradle

• Delete: settings.gradle

• Step 1: Delete old Groovy files

git rm build.gradle settings.gradle

• Step 2: Verify Groovy files removed

Run: git status
Expected: build.gradle and settings.gradle show as "deleted"

---

Task 6: Stage New Kotlin DSL Files

Files:

• Track: settings.gradle.kts

• Track: build.gradle.kts

• Step 1: Stage Kotlin DSL files

git add settings.gradle.kts build.gradle.kts

• Step 2: Verify Kotlin files staged

Run: git status
Expected: Both .kts files show as "new file"

---

Task 7: Build and Verify

Files:

• Verify: build/libs/gitbucket-mcp-plugin-0.1.0.jar

• Step 1: Clean and build

./gradlew clean build

Expected: BUILD SUCCESSFUL, no errors

• Step 2: Verify JAR exists

Run: ls -la build/libs/
Expected: gitbucket-mcp-plugin-0.1.0.jar exists and is ~5-6MB

• Step 3: Verify plugin descriptor in JAR

unzip -l build/libs/gitbucket-mcp-plugin-0.1.0.jar | grep gitbucket-plugin.properties

Expected: Shows gitbucket-plugin.properties entry in JAR

---

Task 8: Commit All Changes

Files:

• Commit: All staged files

• Step 1: Verify all changes staged

Run: git status
Expected: 6 files to be committed:

• build.gradle (deleted)

• settings.gradle (deleted)

• build.gradle.kts (new file)

• settings.gradle.kts (new file)

• .gitignore (modified)

• 4 Gradle wrapper files (new files)

• Step 2: Commit changes

git commit -m "feat: migrate Gradle build to Kotlin DSL

- Convert build.gradle to build.gradle.kts
- Convert settings.gradle to settings.gradle.kts
- Add Gradle wrapper files to version control
- Update .gitignore for wrapper properties
- Configure Java 21 toolchain with Java 17 target
- Use GradleUp shadow plugin 8.3.5 for compatibility"

---

Acceptance Criteria Verification

After completing all tasks:

• build.gradle.kts exists and is valid Kotlin DSL
• settings.gradle.kts exists with plugin management
• Old Groovy files removed
• Gradle wrapper files tracked in git
• Build succeeds with ./gradlew build
• Fat JAR produced at build/libs/gitbucket-mcp-plugin-0.1.0.jar
• .gitignore includes Gradle exclusions
• README.md already has build instructions (verified in spec review)

---

Notes

• No tests needed for build configuration changes (no production code)
• .gitignore already has !gradle/wrapper/gradle-wrapper.jar - just missing properties exception
• README already documents ./gradlew shadowJar - no changes needed
• Build configuration produces same output as Groovy DSL, just in Kotlin syntax

[michael-conrad]

Superseded by #12 (Testing Pipeline spec) and #14 (Overview). The Kotlin DSL plan is a prerequisite for the testing pipeline but is tracked separately — this plan can be closed once that migration is complete.