Android Studio 3.0 Canary 1: Kotlin tests or Java tests referring to Kotlin classes fail

UPDATE

A bug has been filed for this issue here: https://youtrack.jetbrains.com/issue/KT-17951

UPDATE 2

The bug has been fixed in Android Studio 3.0 Canary 3

Original Post

I just started playing around with Android Studio 3.0 I enabled kotlin support from the get-go. I wrote a really simple Kotlin class in my project:

data class Wallet(val coins: Int) {
    fun add(value: Int): Wallet = Wallet(coins + value)
    fun substract(value: Int): Wallet = if (coins > value) Wallet(coins + value) else throw InsufficientFundsException()
}

Now I wanted to test the class, first I wrote a locally running unittest (test directory) in Kotlin:

class WalletTestKotlin {

    @Throws(Exception::class)
    @Test
    fun add() {
        Assert.assertEquals(22, Wallet(20).add(2).coins.toLong())
        Assert.assertNotEquals(5, Wallet(2).add(13).coins.toLong())
    }
}

It compiles and runs but with the error message:

Class not found: "com.agentknopf.hachi.repository.model.WalletTestKotlin"Empty test suite.

I thus re-wrote the test in Java:

public class WalletTest {

    @Throws(exceptionClasses = Exception.class)
    @Test
    public void add() {
        Assert.assertEquals(22, new Wallet(20).add(2).getCoins());
        Assert.assertNotEquals(5, new Wallet(2).add(13).getCoins());
    }
}

However that test failed as well - this time the Kotlin class "Wallet" couldn't be found:

java.lang.NoClassDefFoundError: com/example/repository/model/Wallet

I wonder if I am missing something ... Running a Java Test, that does not refer to Kotlin classes, but to Java classes only successfully completes.

My project build.gradle file is the default one:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    ext.kotlin_version = '1.1.2-4'
    repositories {
        maven { url 'https://maven.google.com' }
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.0-alpha1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
        maven { url 'https://maven.google.com' }
        mavenCentral()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

The dependencies of my Module-specific build.gradle:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    //Kotlin support
    compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
    //Testing libraries
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    testCompile 'junit:junit:4.12'
    testCompile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    testCompile "org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version"
}