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Java Unit Testing in Java How to Test Single Assertions Make For Better Tests

Enyang Mercy
PLUS
Enyang Mercy
Courses Plus Student 2,339 Points

Unit Testing in java CreditorTest make a new test using tripple A

I don't understand what exactly is required. Can someone explain with details. Thank you

com/teamtreehouse/vending/CreditorTest.java
package com.teamtreehouse.vending;

import org.junit.Test;

import static org.junit.Assert.*;

public class CreditorTest {

    @Test
    public void addingFundsIncrementsAvailableFunds() throws Exception {
        Creditor creditor = new Creditor();

        creditor.addFunds(25);
        creditor.addFunds(25);

        assertEquals(50, creditor.getAvailableFunds());
    }

    @Test
    public void refundingReturnsAllAvailableFunds() throws Exception {
        Creditor creditor = new Creditor();
        creditor.addFunds(10);

        int refund = creditor.refund();

        assertEquals(10, refund);
        assertEquals(0, creditor.getAvailableFunds());
    }
}
com/teamtreehouse/vending/Creditor.java
package com.teamtreehouse.vending;

public class Creditor {
    private int funds;

    public Creditor() {
        funds = 0;
    }

    public void addFunds(int money) {
        funds += money;
    }

    public void deduct(int money) throws NotEnoughFundsException {
        if (money > funds) {
            throw new NotEnoughFundsException();
        }
        funds -= money;
    }

    public int refund() {
        int refund = funds;
        funds = 0;
        return refund;
    }

    public int getAvailableFunds() {
        return funds;
    }

}

1 Answer

Yanuar Prakoso
Yanuar Prakoso
15,193 Points

Hi There

As you see in this section of your code:

@Test
    public void refundingReturnsAllAvailableFunds() throws Exception {
        //This is Arrange:
        Creditor creditor = new Creditor();
        creditor.addFunds(10);
        //This is action
        int refund = creditor.refund();
        //This is asserts:
        assertEquals(10, refund);
        assertEquals(0, creditor.getAvailableFunds());
    }

There are two asserts in the refundingReturnsAllAvailableFunds() Test. You need to make one more Test method called refundingResetsAvailableFundsToZero() and move one of the Asserts into this new Test. You can guess which Assert needs to move from the name of the test, right? Here is how I build the other test:

@Test
  public void refundingResetsAvailableFundsToZero() throws Exception {
    //This is Arrange:    
    Creditor creditor = new Creditor();
    creditor.addFunds(10);

    //This is Act:
    int refund = creditor.refund();

    //This is Asserts:
    assertEquals(0, creditor.getAvailableFunds());
  }

I hope this can help a little