Kwik¶

Property-based testing library for Kotlin.

Main features:

Test-engine agnostic
Multiplatform
No reflection
Configurable built-in generators
Easy way to create and combine generators
Seeded generation for reproducible results

Have a look at the setup and usage

Status¶

This project is discontinued. For property based testing with Kotlin, check out kotest.

How it looks like¶

class PlusOperatorTest {

    @Test
    fun isCommutative() = forAll { x: Int, y: Int ->
        x + y == y + x
    }

    @Test
    fun isAssociative() = forAll(iterations = 1000) { x: Int, y: Int, z: Int ->
        (x + y) + z == x + (y + z)
    }

    @Test
    fun zeroIsNeutral() = forAll(seed = -4567) { x: Int ->
        x + 0 == x
    }
}

For more information, read how to write tests and have a look at the available generators

Motivation¶

Property based testing is great and very powerful. But despite the fact that many good libraries already exist, none of them fully fit my needs.

The known alternatives either:

Are bound to a specific test-engine
Can only be used when compiling kotlin to Java (and cannot be used in multi-platform projects)
Relies on reflection, making the tests slower and make some errors detectable only at runtime
Do not allow enough freedom and safety to customize existing generators
Force the user to add unwanted dependencies in the classpath

Requirements¶

Kotlin version: 1.4.0 or newer
JDK version: 8, 11 or 15

Setup¶

Example of setup using gradle.

repositories {
    jcenter()
}

dependencies {
    testCompile("com.github.jcornaz.kwik:kwik-core-jvm:$kwikVersion")
}

For more information, read the setup

Contribute¶

See how to contribute