JUnit 6 Kotlin Workshop

A practical workshop with runnable examples of JUnit 6 features in Kotlin/JVM.

Related projects:

• JUnit Workshop — the complete Java counterpart of this Kotlin workshop
• Selenium Example (JUnit 6 branch) — a real-world Java Selenium WebDriver framework built on JUnit 6

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Note

This project is a work in progress and is being expanded incrementally. The README documents only the examples that are already available in the repository.

Table of contents

• Who is this for?
• Quick start
• Prerequisites
• Versions
• Available examples
• Start here
• Command examples
• Test report
• Project structure
• Useful links
• License

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Who is this for?

Audience	What you will get
QA engineers new to JUnit 6	Small runnable examples of core JUnit features
Kotlin developers	JUnit examples written with Kotlin/JVM syntax and idioms
Java developers learning Kotlin	Familiar JUnit concepts shown in Kotlin
Workshop facilitators	A project that can be expanded topic by topic

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Quick start

git clone https://github.com/a-oleynik/junit-kotlin-workshop.git
cd junit-kotlin-workshop

Run the tests on Linux, macOS, or Git Bash:

./gradlew clean test

Run the tests on Windows Command Prompt or PowerShell:

gradlew.bat clean test

The Gradle Wrapper downloads and uses the required Gradle version automatically.

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Prerequisites

Tool	Version	Notes
JDK	21	Used by the Kotlin JVM toolchain
Gradle	9.6.0	Provided by the included Gradle Wrapper
IDE	Any	IntelliJ IDEA is recommended

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Versions

Component	Version
Kotlin	2.4.0
JUnit	6.1.2
Java toolchain	21
Gradle Wrapper	9.6.0

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Available examples

Feature	Test class
Basic assertions: equality, booleans, nullability, identity, and fail	AssertTest
Disabling a test method or an entire test class with @Disabled	DisabledTest
Test lifecycle with @BeforeEach, @AfterEach, @BeforeAll, and @AfterAll	FixturesTest
Exception testing with assertThrows	ExceptionTest
Time limits with assertTimeout and @Timeout	TimeoutTest

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Start here

The examples can be explored in this order:

1. AssertTest — learn the basic JUnit assertions.
2. FixturesTest — observe the test lifecycle.
3. ExceptionTest — verify expected exceptions.
4. DisabledTest — disable individual tests or a complete test class.
5. TimeoutTest — apply time limits to test execution.

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Command examples

The examples below use the Gradle Wrapper. On Windows Command Prompt or PowerShell, replace ./gradlew with gradlew.bat.

Run all tests

./gradlew clean test

Run a single test class

./gradlew test --tests "*AssertTest"

Run a single test method

./gradlew test --tests "*AssertTest.assertEquals verifies multiplication result"

Run multiple test classes

./gradlew test --tests "*AssertTest" --tests "*ExceptionTest"

Compile and run all verification tasks

./gradlew clean build

Build without running tests

./gradlew build -x test

Run tests with additional diagnostic output

./gradlew test --info

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Test report

The test task generates a Gradle HTML report:

build/reports/tests/test/index.html

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Project structure

.
├── gradle/wrapper/
│   ├── gradle-wrapper.jar
│   └── gradle-wrapper.properties
├── src/
│   ├── main/kotlin/com/oleynik/qa/workshop/kotlin/junit/
│   │   ├── model/       # Example production models
│   │   └── Utils.kt     # Utility used by timeout examples
│   └── test/kotlin/com/oleynik/qa/workshop/kotlin/junit/
│       └── general/     # Assertions, fixtures, exceptions, disabled tests, and timeouts
├── build.gradle.kts
├── gradle.properties
├── gradlew
├── gradlew.bat
└── settings.gradle.kts

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Useful links

• JUnit Workshop — comprehensive JUnit examples in Java
• TestNG Workshop — companion TestNG examples for side-by-side comparison
• Selenium Example (JUnit 6 branch) — a real-world Selenium WebDriver framework built on JUnit 6
• JUnit 6 Released — Clean-Up, Modernization & Minimal Disruption
• JUnit 6 User Guide
• Kotlin documentation
• Gradle User Manual
• Gradle Wrapper
• Gradle Kotlin DSL Primer
• Testing JVM projects with Gradle

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License

This project is licensed under the Apache License 2.0. See LICENSE for details.

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