StateTest.kt

package org.vld.sdp.behavioral

import org.assertj.core.api.Assertions.* // ktlint-disable no-wildcard-imports
import org.junit.jupiter.api.DisplayName
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.TestInstance

@TestInstance(TestInstance.Lifecycle.PER_CLASS)
class StateTest {

    @Test
    @DisplayName("Given a vending machine. When proceed with the steps. Then handle the request in each step as per current vending machine state")
    fun givenVendingMachine_whenProceedWithSteps_thenHandleRequestInEachStepAsPerCurrentVendingMachineState() {
        // Given
        val vendingMachine = VendingMachine()
        // When
        // proceed with each step of the vending machine
        vendingMachine.proceed() // execute show products step and set the next vending machine state
        vendingMachine.proceed() // execute select product step and set the next vending machine state
        vendingMachine.proceed() // execute deposit money step and set the next vending machine state
        // collect the overall result of all the steps
        val result = vendingMachine.proceed() // execute deliver product step and set the initial vending machine state
        // Then
        val expectedResult = listOf("Show Products", "Select Product", "Deposit Money", "Deliver Product")
        assertThat(result).isEqualTo(expectedResult)
    }
}