Kotlin Unit Testing Examples

Last update: Dec 11, 2022

Overview

Kotlin Unit Testing Examples

Table of Contents

Application
Gradle, Kotlin & Groovy
Junit4
Junit5
KotlinTest
Spek
Mockito
Mockito-Kotlin
Mockk
Strikt

This repository contains examples of basic unit tests written in Kotlin. In specific directories you can find gradle buildscript with needed dependencies and configuration, simple unit test and parameterized test.

All sample projects was verified under Gradle 4.10.2 and Intellij IDEA 2018.2.4

Application

UseCase which provides empty string - to showcase structure of test methods

DistanceConverter - converts meters to kilometers in parameterized tests

MVP - Model-View-Presenter contract

Gradle, Kotlin & Groovy

This Gradle project is by default configured with Gradle’s Kotlin DSL

The equivalent Groovy build are still available for you copy&pasting pleasures, they have been renamed as build.gradle.groovy

You can switch between Groovy and Kotlin by running the script $ ./toggle-kotlin-groovy.sh

Junit4

https://junit.org/junit4/

Attach to project

dependencies{
    testCompile group: 'junit', name: 'junit', version: '4.12'
}

Junit5

https://junit.org/junit5/

Attach to project

dependencies {
    testCompile('org.junit.jupiter:junit-jupiter-api:5.3.1')
    testCompile('org.junit.jupiter:junit-jupiter-params:5.3.1')
    testRuntime('org.junit.jupiter:junit-jupiter-engine:5.3.1')
}

test {
    useJUnitPlatform()
    testLogging {
        events "passed", "skipped", "failed"
    }
}

KotlinTest

https://github.com/kotlintest/kotlintest

Attach to project

dependencies{
    testCompile 'io.kotlintest:kotlintest-runner-junit5:3.1.10'
}

Spek

https://spekframework.org version 2.x

Attach to project

repositories {
    mavenCentral()
    maven { url "https://dl.bintray.com/spekframework/spek-dev" }

}

test {
    useJUnitPlatform {
        includeEngines 'spek2'
    }
}

dependencies {
    testImplementation ('org.spekframework.spek2:spek-dsl-jvm:2.0.0-rc.1')  {
        exclude group: 'org.jetbrains.kotlin'
    }
    testRuntimeOnly ('org.spekframework.spek2:spek-runner-junit5:2.0.0-rc.1') {
        exclude group: 'org.junit.platform'
        exclude group: 'org.jetbrains.kotlin'
    }

    testCompile('org.junit.jupiter:junit-jupiter-api:5.3.1')


    // spek requires kotlin-reflect, can be omitted if already in the classpath
    testRuntimeOnly "org.jetbrains.kotlin:kotlin-reflect:$kotlin_version"
}

For Spek you may also need additional Intellij or Android Studio plugin

Mockito

https://site.mockito.org

Add to project

repositories {
    mavenCentral()
    jcenter()
}


dependencies {
    testCompile "org.mockito:mockito-core:2.23.0"

    testCompile group: 'junit', name: 'junit', version: '4.12'
}

Mockito-Kotlin

https://github.com/nhaarman/mockito-kotlin

Add to project

repositories {
    mavenCentral()
    jcenter()
}


dependencies {
    testCompile "org.mockito:mockito-core:2.23.0"
    testCompile "com.nhaarman.mockitokotlin2:mockito-kotlin:2.0.0-RC1"

    testCompile group: 'junit', name: 'junit', version: '4.12'
}

Mockk

https://github.com/mockk/mockk

Add to project

dependencies {
    testCompile group: 'junit', name: 'junit', version: '4.12'
    testImplementation "io.mockk:mockk:1.8.12"
}

Strikt

https://strikt.io

Add to project

dependencies {
    testImplementation("io.strikt:strikt-core:0.17.0")
}

Comments

Convert project to Gradle+Kotlin

While I was doing this small pull request earlier, I realized that your project was exactly the playground I needed (neither trivial not too large, with tests) for something I had in mind :

Showing by example how to convert a Gradle project to the Kotlin DSL.

It will be a follow-up to this article I wrote and I plan to show it at a Kotlin Meetup in Berlin.

https://blog.kotlin-academy.com/gradle-kotlin-the-missing-piece-of-the-puzzle-7528a85f0d2c

If you prefer to stay with Gradle/Groovy, no hard feeling :)

It should work fine with Intellij IDEA 2018.+ and Android Studio 3.2+, tell me if you encounter problems.

opened by jmfayard 5

Improve kotlintest parametrized test

Personally I would write this test like this. Both cleaner to read, and a better test output

java.lang.AssertionError: 1 elements passed but expected 2

The following elements passed:
(500, 0.5)

The following elements failed:
(750, 0.8) => 0.75 should be equal to 0.8

opened by jmfayard 4

New KotlinTest module for a Kotlin Academy article

Hello Jaroslaw,

I have a plan to write an article about KotlinTest for https://blog.kotlin-academy.com

I contributed to this project in the past (the asciidoc and Gradle Kotlin DSL parts), and I thought it would be handy to have the code samples I will use to be part of this project. It's a good way to have a unit tests playground already setup, and people can compare with what is available in the other unit tests frameworks.

I don't want to bother you each time I make a modification to my code samples though.

Would you mind to give me write access to this repo?

Jean-Michel Fayard

opened by jmfayard 1
Invert actual and expected

When using shouldBe, the syntax should be something similar to "this should be that", and not "that should be this". With this change, the semantics are fixed

opened by LeoColman 0
Use Versions.xx in README.adoc

Hello again,

So first I just wanted to handle the nice comments added by gildor in the previous pull request https://github.com/rozkminiacz/KotlinUnitTesting/pull/2

Then I said, why not update buildSrc/src/main/kotlin/Versions.kt? Notably Kotlin 1.3.0. The project still works nice!

Then I realized I had a problem, the README does not auto-update itself if I update Versions.kt

Then I realized there is a solution for that too. I could use variables in the README if I convert it from Markdown to https://asciidoctor.org/ (which is like Markdown for the simple things, but without the pile of hacks when you want to do something more complex. Because then I can generate the variables for the README from Gradle!

Ok, so that was more time than I expected but it was fun!

opened by jmfayard 0
Add TestNG to samples
Create new module named testng with samples of TestNG framework usage. testng.org/

[ ] Gradle and Intellij configuration

[ ] Unit test example

[ ] Parameterized test example

[ ] Example of test grouping

enhancement help wanted
opened by rozkminiacz 0

Owner

Jarosław

GitHub https://kotlintesting.com

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