Kotlin + JUnit5 + Nested classes

test.kt

fun value(str: String): Int {
    println(str)
    return 0
}

fun test(str: String) {
    println("【Executed Test: $str】")
}

class Test1 {
    constructor() {
        println("Test1 constructor called")
    }

    val v1_1 = value("v1_1")

    companion object {
        @BeforeAll @JvmStatic
        fun beforeAll() = println("@: Test1 BeforeAll")
    }

    @BeforeEach
    fun beforeEach() = println("@: Test1 BeforeEach")

    @Test
    fun test1_1() = test("test1_1")

    @Test
    fun test1_2() = test("test1_2")

    @Nested
    inner class Test2 {
        constructor() {
            println("Test2 constructor called")
        }

        val v2_1 = value("v2_1")
        val v2_2 = value("v2_2")
        val v2_3 by lazy { value("v2_3 (by lazy)") }

        @Test
        fun test2_1() = test("test2_1")

        @Test
        fun test2_2() {
            test("test2_2")
            v2_3
        }

        @Test
        fun test2_3() {
            test("test2_3")
            v2_3
        }
    }

    @Nested
    inner class Test3 {
        constructor() {
            println("Test3 constructor called")
        }

        val v3_1 = value("v3_1")

        @Test
        fun test3_1() = test("test3_1")

        @Nested
        inner class Test4 {
            constructor() {
                println("Test4 constructor called")
            }

            val v4_1 = value("v4_1")

            @Test
            fun test4_1() = test("test4_1")
        }
    }
}

// =>
//   @: Test1 BeforeAll
//   v1_1
//   Test1 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test1_1】
//   v1_1
//   Test1 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test1_2】
//   v1_1
//   Test1 constructor called
//   v2_1
//   v2_2
//   Test2 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test2_1】
//   v1_1
//   Test1 constructor called
//   v2_1
//   v2_2
//   Test2 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test2_2】
//   v2_3 (by lazy)
//   v1_1
//   Test1 constructor called
//   v2_1
//   v2_2
//   Test2 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test2_3】
//   v2_3 (by lazy)
//   v1_1
//   Test1 constructor called
//   v3_1
//   Test3 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test3_1】
//   v1_1
//   Test1 constructor called
//   v3_1
//   Test3 constructor called
//   v4_1
//   Test4 constructor called
//   @: Test1 BeforeEach
//   【Executed Test: test4_1】