Can someone show me how to make a unit test for this method?

Question

I want to make a unit test for a game I have made, this code below is a simple move command for a grid-based game whereby when the user clicks a button the method is attached to, the player is moved up 1 row.

public String moveUp() {     //Allows player to move when corresponding command is entered
        int targetRow;
        int targetCol;

        targetRow = goldMiner.getRow() - 1;
        targetCol = goldMiner.getCol();

        String response = "";
        //If player does not have enough stamina they will not be allowed to move
        if (goldMiner.getStamina() <= 0) {
            response = "You are out of Stamina";
        //Stops player from moving outside of map
        } else if (targetRow < 0) {
            response = "You can't move that way";
        //If all parameters are met allows player to move in corresponding direction
        } else {
            PlayerMove(targetRow, targetCol);
            response = "You moved Up";
        }
        return response;
    }

Welcome to Stack Overflow. Please take the [tour] to learn how Stack Overflow works and read [ask] on how to improve the quality of your question. Then check the [help/on-topic] to see what questions you can ask. You might want to check other questions like https://stackoverflow.com/questions/8751553/how-to-write-a-unit-test — Progman, May 31 '20 at 10:48

score 2 · Answer 1 · answered May 31 '20 at 10:32

2

For this method, you need three unit tests to cover all the code and you also need to mock goldMiner. The unit test would be like the below code:

public UnitTest {
  Mock GoldMiner goldMiner;
  @Autowired
  Service service; // assume moveUp method in this service 
  @BeforeEach
  void setUp() {
        goldMiner = mock(GoldMiner.class);
  }

  @Test
  public void shouldGetStamia_thenReturnOutof() {
   // You are out of Stamina
   when(goldMiner.getStamina()).thenReturn(-1);
   String response = service.moveUp();
   assertEquals(response, "You are out of Stamina");
  }

  //then another two cases are similar
  @Test
  public void shouldRowLessThanZero_thenCannotMove() {

  }

  @Test 
  public void shouldNormal_thenMoveUp() {

  }
}

answered May 31 '20 at 10:32

PatrickChen

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This looks really great and I appreciate the efforts to help me, I tried implementing it into my code but couldn't get it to work, I think it might be a little beyond my level of skill at the moment :( – Mirdon May 31 '20 at 11:10
Try to write some simple method and unit test follows some code example, learn to use `mock` is very important in the unit test. – PatrickChen May 31 '20 at 11:37
Are you using a library for this? – Scratte May 31 '20 at 15:44
yes, mockito and junit – PatrickChen Jun 01 '20 at 01:20

score 1 · Answer 2 · 2020-05-31T10:41:08.040

I suggest using JUnit5.

One simple example:

import org.junit.Test;
import org.junit.Assert;

public class Tests {

  @Test     //This is needed
  public void testOne() {
    String response = moveUp(); //Call method
    Assert.assertEquals("expectedValue", response); //Comparing expectedValue with response
  }
}

This method will test, whether response equals to the expected value (you will have to replace "expectedValue" with the real value).

I highly suggest to use an IDE like Eclipse to do Unit-tests. In Eclipse, you will have to import JUnit like explained here.

Please note: You can also have more than one test-method in Tests.java.

Can someone show me how to make a unit test for this method?

2 Answers2