Getting started

This page takes a JVM project from nothing to a working mock and a working fake. For Kotlin Multiplatform projects, see Setup.

  1. Apply the Gradle plugins and activate the test helper:

    build.gradle.kts
    plugins {
    kotlin("jvm") version "2.4.20"
    id("com.google.devtools.ksp") version "2.3.12" (1)
    id("org.kodein.mock.mockmp") version "3.5.5" (2)
}

kotlin {
    jvmToolchain(11)
    // Your Kotlin configuration
}

mockmp { (3)
    onTest {
        withHelper() // or withHelper(junit5)
    }
}
    1 Apply the KSP plugin that corresponds to the Kotlin version you are using.
    2 Apply the MocKMP plugin.
    3 Apply MocKMP to your test source sets, after declaring the kotlin targets.

  2. Create a test class that declares injected mocks and fakes:

    MyTest.kt
    class MyTest : TestsWithMocks() { (1)
    override fun setUpMocks() = mocker.injectMocks(this) (2)

    @Mock lateinit var view: View
    @Fake lateinit var model: Model

    val controller by withMocks { Controller(view = view, firstModel = model) }

    @Test fun controllerTest() {
        every { view.render(isAny()) } returns true
        controller.start()
        verify { view.render(model) }
    }
}
    1 The TestsWithMocks super class eases the use of MocKMP in your tests, but is not mandatory.
    2 This is mandatory and cannot be generated. You need to build your project at least once for your IDE to see the injectMocks function.

    Every property annotated by @Mock, annotated by @Fake or delegated to withMocks is reset fresh between each test.

That’s it! From here, Mocking types and Faking types explain what you can do with a mock and a fake, and Setup covers the other platforms.