Basic Github action for Kotlin (Gradle): build and test

I recently started working with Kotlin. And unlike in my Rust and Scala projects, Github did not suggest a CI workflow for me.

You can use a bog-standard Java workflow and just add two commands:

chmod +x gradlew

./gradlew test --no-daemon

Here is the workflow (goes into .github/workflows/ci.yml:

name: CI

on:
  push:
    branches: [ main ]
  pull_request:
    branches: [ main ]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v4
      - name: Set up JDK
        uses: actions/setup-java@v4
        with:
          distribution: 'temurin'
          java-version: '21'
      - name: Grant execute permission for gradlew
        run: chmod +x gradlew
      - name: Run tests
        run: ./gradlew test --no-daemon

If you want some more info in your test output, you can add this to your build.gradle.kts as a top level definition:

tasks.test {
    useJUnitPlatform()
    testLogging {
        events("passed", "skipped", "failed")
        exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
        showStandardStreams = true
    }
}

Personally I'm using kotest, and my dev requirements look like this:

dependencies {
    // other stuff
    
    testImplementation(kotlin("test"))
    testImplementation("io.kotest:kotest-runner-junit5:5.8.0")
    testImplementation("io.kotest:kotest-assertions-core:5.8.0")
}