Test Directory Exists + Kotlin Collector

✓ Guardrail ↓ Collector Beta Devex Build And Ci

Enforce Test Directory Exists using data collected by Kotlin Collector. Automatically check devex build and ci standards on every PR.

Guardrail: Ensures a `src/test/kotlin` directory (or the equivalent for Android / Multiplatform layouts) exists with test sources. Skips on non-Kotlin projects.

Data Source: Analyze Kotlin projects to collect project metadata, dependencies, CI/CD command tracking, and test coverage. Supports Gradle (Kotlin & Groovy DSL) and Maven. Detects the Kotlin version, JVM/Android/Multiplatform targets, test frameworks (JUnit, Kotest, MockK), and detekt/ktlint.

Get Started View on GitHub

How Kotlin Collector Powers This Guardrail

The Kotlin Collector gathers metadata from your languages, build systems. This data flows into Lunar's Component JSON, where the Test Directory Exists guardrail evaluates it against your standards.

When enabled, this check runs automatically on every PR and in AI coding workflows, providing real-time enforcement with actionable feedback.

↓ Kotlin Collector Gathers Data Collector

Extracts metadata from code, configs, and tool outputs

{ } Component JSON

Data centralized in structured format for evaluation

✓ Test Directory Exists Checks Guardrail

Pass/fail result with actionable feedback in PRs

Quick Start Configuration

Add both the collector and policy to your lunar-config.yml to enable this guardrail.

📄 lunar-config.yml

# Step 1: Enable the Kotlin Collector
collectors:
  - uses: github://earthly/lunar-lib/collectors/kotlin@v1.0.5
    # with: ...

# Step 2: Enable the Kotlin Project Guardrails
policies:
  - uses: github://earthly/lunar-lib/policies/kotlin@v1.0.5
    include: [test-directory-exists]
    # with: ...

What Kotlin Collector Collects

This collector gathers the following data that the Test Directory Exists guardrail evaluates.

Collector code

`project`

Analyzes Kotlin project structure by detecting build.gradle.kts, build.gradle (Groovy DSL applying a Kotlin plugin), settings.gradle(.kts), pom.xml (with kotlin-maven-plugin), gradle/libs.versions.toml (version catalog), gradle.lockfile, the Gradle wrapper, detekt/ktlint config, and the test source directory. Parses the Kotlin compiler version (from the Gradle kotlin(...) plugin, pom <kotlin.version>, or the version catalog), project name/version, Gradle version, detected test frameworks, framework flags (Ktor, Spring, Compose, Coroutines), and the JVM / Android / Multiplatform target. Skips when no *.kt / *.kts source files are present. Writes project metadata to .lang.kotlin.

Collector code

`dependencies`

Extracts direct dependencies from build.gradle.kts / build.gradle (dependencies block, including libs. version-catalog references), pom.xml, or gradle/libs.versions.toml. When gradle.lockfile is present, also extracts resolved transitive versions. Writes dependency data to .lang.kotlin.dependencies.

Collector ci-before-command

`cicd`

Records every kotlinc / kotlin command executed in CI pipelines along with the compiler version. Writes command strings and version info to .lang.kotlin.cicd for audit trails and build reproducibility analysis. Gradle and Maven invocations are already tracked by the java collector's gradle-cicd / maven-cicd sub-collectors, so this focuses on direct Kotlin-compiler usage.

Collector ci-after-command

`test-coverage`

Extracts coverage percentage from Kover XML reports (build/reports/kover/report.xml) after a Gradle test / koverXmlReport run. Kover is the Kotlin-native coverage tool; JaCoCo is intentionally left to the java collector's test-coverage sub-collector — matching the per-language convention (scala→scoverage, java→jacoco, kotlin→kover) and avoiding a double-write to the normalized .testing.coverage path. Writes to .lang.kotlin.tests.coverage and .testing.coverage.

Example Data Flow

Here's an example of the data that Kotlin Collector writes to the Component JSON, which Test Directory Exists then evaluates.

{ } component.json From Kotlin Collector

{
  "lang": {
    "kotlin": {
      "version": "1.9.22",
      "build_systems": ["gradle"],
      "build_gradle_kts_exists": true,
      "build_gradle_exists": false,
      "settings_gradle_exists": true,
      "pom_xml_exists": false,
      "version_catalog_exists": true,
      "gradlew_exists": true,
      "lockfile_exists": false,
      "detekt_configured": true,
      "ktlint_configured": false,
      "test_directory_exists": true,
      "project_name": "my-service",
      "project_version": "0.1.0",
      "gradle_version": "8.5",
      "target": "jvm",
      "is_multiplatform": false,
      "is_android": false,
      "test_frameworks": ["junit", "kotest", "mockk"],
      "frameworks": ["ktor", "coroutines"],
      "source": { "tool": "gradle", "integration": "code" },
      "cicd": {
        "cmds": [
          { "cmd": "kotlinc src -include-runtime -d app.jar", "version": "1.9.22" }
        ]
      },
      "tests": {
        "coverage": {
          "percentage": 81.3,
          "source": { "tool": "kover", "integration": "ci" }
        }
      },
      "dependencies": {
        "direct": [
          { "path": "io.ktor:ktor-server-core", "version": "2.3.7" },
          { "path": "org.jetbrains.kotlinx:kotlinx-coroutines-core", "version": "1.7.3" }
        ],
        "transitive": [
          { "path": "org.jetbrains.kotlin:kotlin-stdlib", "version": "1.9.22" }
        ],
        "source": { "tool": "gradle", "integration": "code" }
      }
    }
  },
  "testing": {
    "coverage": {
      "percentage": 81.3,
      "source": { "tool": "kover", "integration": "ci" }
    }
  }
}

Configuration Options

Kotlin Project Guardrails Inputs

Input	Required	Default	Description
`min_kotlin_version`	Optional	`1.8`	Minimum required Kotlin compiler version (e.g., "1.8", "1.9", "2.0"). Compared with semantic-version semantics — "1.8" matches 1.8.x and above, but rejects 1.7.x.

Learn More

Guardrail · Kotlin Project Guardrails Test Directory Exists View all compatible integrations

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Collector Kotlin Collector View full documentation

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