Simple Kotlin Application with Gradle

build.gradle.kts

plugins {
	kotlin("jvm") version "1.3.50"
	application
}

repositories {
	jcenter()
}

dependencies {
	implementation(kotlin("stdlib", "1.3.50"))
	testImplementation("junit:junit:4.12")
}

application {
	mainClassName = "app.smth.kotlin.MyLibrary"
}

MyLibrary.kt

package app.smth.kotlin

data class Language(val name: String, val hotness: Int)

class MyLibrary {
	fun kotlinLanguage() = Language("Kotlin", 10)

	companion object {
		@JvmStatic
		fun main(args: Array<String>) {
			val languageName = MyLibrary().kotlinLanguage().name
			println("My favorite language is $languageName")
		}
	}
}

MyLibraryTest.kt

package app.smth.kotlin

import org.junit.Assert.assertEquals
import org.junit.Test

class MyLibraryTest {
	@Test fun testMyLanguage() {
		assertEquals("Kotlin", MyLibrary().kotlinLanguage().name)
		assertEquals(10, MyLibrary().kotlinLanguage().hotness)
	}
}