language plugin

kotlin

`kotlin` is a Syrus plugin gem that layers Kotlin/JVM language awareness on top of the generic Java plugin. It lives at `plugins/kotlin/` inside the Syrus repository and applies to Kotlin/JVM services, CLIs, libraries, and mixed-language repositories with Kotlin components.

kotlinSource

kotlin

kotlin is a Syrus plugin gem that layers Kotlin/JVM language awareness on top of the generic Java plugin. It lives at plugins/kotlin/ inside the Syrus repository and applies to Kotlin/JVM services, CLIs, libraries, and mixed-language repositories with Kotlin components.

What it provides

Extension point	What it does
`:prepare_detector`	Detects Kotlin source files (`.kt`), Kotlin scripts (`.kts`), Gradle Kotlin DSL files (`build.gradle.kts`, `settings.gradle.kts`), Kotlin JVM Gradle plugin declarations, and conventional Kotlin source/test paths (`src/main/kotlin`, `src/test/kotlin`). It depends on the Java plugin and reuses Java's Gradle/Maven prepare commands instead of duplicating build-tool command logic.
`:prompt_injector`	Reminds agents to treat Kotlin paths and Gradle Kotlin DSL files as JVM project signals, prefer `./gradlew`, and use repository-declared JDK/Kotlin Gradle plugin versions.
`:review_criteria_provider`	Adds Kotlin/JVM review criteria for swallowed coroutine cancellation and unsafe null assertions at external boundaries.

Typed grader examples

Kotlin/JVM projects use the Java plugin's Gradle typed grader:

grade:
  - type: gradle
    tasks: [test]

Mixed Java/Kotlin monorepo with a nested JVM project:

project:
  id: api
  label: API service
  kind: service

grade:
  - type: gradle
    name: api-tests
    tasks: [test]
    when_files_changed:
      - "src/main/java/**/*"
      - "src/main/kotlin/**/*"
      - "src/test/java/**/*"
      - "src/test/kotlin/**/*"
      - "build.gradle.kts"
      - "settings.gradle.kts"
      - "gradle/**/*"
      - "gradlew"

Boundary with Android and Kotlin Multiplatform

This plugin owns only generic Kotlin/JVM conventions: Kotlin source-layout detection, Gradle Kotlin DSL signals, Kotlin JVM plugin detection, and reuse of Java's JVM prepare/grader machinery. Kotlin Multiplatform, native/iOS targets, Android Gradle Plugin behavior, Android SDK setup, emulator/device requirements, and Android runtime concerns are intentionally out of scope.

Loading the plugin

The plugin registers itself via a Rails engine to_prepare hook once gem "kotlin", path: "plugins/kotlin" is bundled. It depends on the bundled java plugin.

Running tests

From the repo root:

bin/rspec plugins/kotlin/spec plugins/java/spec/gradle_grader_type_spec.rb