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

Posted by Chance Edward
Chance Edward
4,507 Points

Unit testing in java

Now that we know that we should only have one behavior that we are asserting per test, can you help me break out the refundingReturnsAllAvailableFunds test case into a new one?

How about making a new test that does the same, Arrange, Act and Assert named refundingResetsAvailableFundsToZero that separates out that final assertion in the first test.

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;
    }

}