Tests for Beto to not be paranoid 😳

GumballMachineTest.java

package tech.jaredhasson;

import static org.junit.jupiter.api.Assertions.assertAll;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assumptions.assumeTrue;
import static org.junit.jupiter.api.Assumptions.assumingThat;

import org.junit.jupiter.api.*;

import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.time.DayOfWeek;
import java.time.LocalDateTime;

@DisplayName("Gumball Machine Tests")
public class GumballMachineTest {

  private static Logger logger = LoggerFactory.getLogger(GumballMachineTest.class);

  private GumballMachine classUnderTest;

  @Test
  @DisplayName("Before initializing, classUnderTest should be null")
  public void nullTest() {
    assertNull(classUnderTest);
  }

  @BeforeAll
  public static void setUp() {
    logger.info("Starting tests");
  }

  @AfterAll
  public static void tearDown() {
    logger.info("Finished testing");
  }

  @Nested
  @DisplayName("Add Gumballs Tests")
  public class AddGumballsTest {

    @BeforeEach
    public void setUp() {
      classUnderTest = new GumballMachine();
      classUnderTest.setCurrentState(new EmptyState());
    }

    @AfterEach
    public void tearDown() {
      classUnderTest = null;
    }

    @Test
    @DisplayName("Adding gumballs switches to filled state")
    public void addGumballs_emptyState_filledState() {
      assertNotNull(classUnderTest);
      int numOfGumballs = 5;
      classUnderTest.addGumballs(numOfGumballs);
      assertEquals(numOfGumballs, classUnderTest.getCount());
      assertTrue(classUnderTest.getCurrentState() instanceof FilledState);
    }

    @Test
    @DisplayName("Adding gumballs remains in filled state")
    public void addGumballs_filledState_filledState() {
      assertNotNull(classUnderTest);
      classUnderTest.setCurrentState(new FilledState());
      int numOfGumballs = 5;
      classUnderTest.addGumballs(numOfGumballs);
      assertEquals(numOfGumballs, classUnderTest.getCount());
      assertTrue(classUnderTest.getCurrentState() instanceof FilledState);
    }

    @ParameterizedTest(name = "adding {0} gumballs should result in a count of {0}")
    @DisplayName("Parameterized test for adding gumballs")
    @CsvSource({"3", "5", "6"})
    public void addGumballs_emptyState_filledState_param(int numGumballs) {
      assertNotNull(classUnderTest);
      classUnderTest.addGumballs(numGumballs);
      assertEquals(numGumballs, classUnderTest.getCount());
      assertTrue(classUnderTest.getCurrentState() instanceof FilledState);
    }
  }

  @Nested
  @DisplayName("Add Quarters Test")
  public class AddQuarterTests {
    @BeforeEach
    public void setUp() {
      classUnderTest = new GumballMachine();
      classUnderTest.setCurrentState(new EmptyState());
    }

    @AfterEach
    public void tearDown() {
      classUnderTest = null;
    }

    @Test
    @Disabled
    @DisplayName("Disabled test")
    public void addPenny() {
      logger.info("Should never be run");
    }

    @Test
    @DisplayName("Inserting a quarter in empty state should switch to quarter empty state")
    public void insertQuarter_emptyState_quarterEmptyState() {
      assertNotNull(classUnderTest);
      classUnderTest.insertQuarter();
      assertTrue(classUnderTest.getCurrentState() instanceof QuarterEmptyState);
    }

    @Test
    @DisplayName("Inserting a quarter in filled state should switch to filled quarter state")
    public void insertQuarter_filledState_filledQuarterState() {
      assertNotNull(classUnderTest);
      classUnderTest.setCurrentState(new FilledState());
      classUnderTest.insertQuarter();
      assertTrue(classUnderTest.getCurrentState() instanceof FilledQuarterState);
    }
  }

  @Nested
  @DisplayName("Remove Quarters Test")
  public class RemoveQuarterTests {
    @BeforeEach
    public void setUp() {
      classUnderTest = new GumballMachine();
      classUnderTest.setCurrentState(new EmptyState());
    }

    @AfterEach
    public void tearDown() {
      classUnderTest = null;
    }

    @Test
    @DisplayName("Removing a quarter in empty state should throw exception")
    public void removeQuarter_emptyState_exception() {
      assertNotNull(classUnderTest);
      assertThrows(IllegalStateException.class, () -> classUnderTest.removeQuarter());
    }

    @Test
    @DisplayName(
        "Removing a quarter in filled quarter state on Sunday should switch to empty quarter state")
    public void removeQuarter_filledQuarterState_emptyQuarterState() {
      assertNotNull(classUnderTest);
      classUnderTest.setCurrentState(new FilledQuarterState());
      DayOfWeek dayOfWeek = LocalDateTime.now().getDayOfWeek();
      assumingThat(
          dayOfWeek == DayOfWeek.SUNDAY,
          () -> {
            classUnderTest.removeQuarter();
            assertTrue(classUnderTest.getCurrentState() instanceof FilledState);
          });
    }
  }

  @Nested
  @DisplayName("Turn Handle Test")
  public class TurnHandleTests {
    @BeforeEach
    public void setUp() {
      classUnderTest = new GumballMachine();
      classUnderTest.setCurrentState(new EmptyState());
    }

    @AfterEach
    public void tearDown() {
      classUnderTest = null;
    }

    @Test
    @Tag("conditional")
    @DisplayName("Turn handle in the United States should switch")
    public void turnHandle_filledQuarterState_quarterEmptyState() {
      classUnderTest.setCurrentState(new FilledQuarterState());
      classUnderTest.increaseGumballCount(1);
      assumeTrue(System.getProperty("user.country").equals("US"));
      classUnderTest.turnHandle();
      assertAll(
          "should empty the machine of gumballs and quarter",
          () -> assertTrue(classUnderTest.getCurrentState() instanceof EmptyState),
          () -> assertEquals(0, classUnderTest.getCount()));
    }
  }
}