CODEWITHSUNDEEP
javajunitvoid
Seeruttun Kervin
Seeruttun Kervin

Reputation: 33

Junit Testing with void method

I have to create a JUnit test for the following class, but I cannot do the test for the method deposit.

public class Account {
    private int balance;
    private float Interest_Rate =10;

    public Account() {
        this.balance = 0;
    }
    public void deposit(int amount) {       
        balance = balance+amount;
    }
}

@Test
public void testdeposit() {
    Account i = new Account();
    assertEquals("Result",75,i.deposit(25));
}

Upvotes: 1

Views: 19204

Answers (3)

NachoGobet
NachoGobet

Reputation: 31

You could have a System.out.println in the method and tell the JUnit test to ask for stdout:

private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();

and then

@Before
public void setUpStreams() {
    System.setOut(new PrintStream(outContent));
}

@After
public void cleanUpStreams() {
    System.setOut(null);
}

finally

assertEquals(<here goes your expected string>, outContent.toString());

Upvotes: 0

Bor Laze
Bor Laze

Reputation: 2506

Testing private fields/methods does not have sense.

In your case, balance is 'write-only' variable; it should have public accessor (as written above), or field should be used in other methods like

public int income() {
  if(balance == 0 ) return 0;
  if(balance < 100) return 10;
  if(balance < 1000) return 15;
  return 20;
}

In this case your test should be like

@Test
public void deposit(){
  Account acc = new Account();
  acc.deposit(150);
  assertEquals("Result ", 15, acc.income());
}

Don't test implementation; test interface.

Upvotes: 0

davidxxx
davidxxx

Reputation: 131326

You could add a getBalance() method in the Account class :

 public int getBalance(){
      return balance;
    }

And use it to do the assertion :

@Test
public void deposit(){
    Account i = new Account();
    i.deposit(25)
    assertEquals("Result",25, i.getBalance());
}

Generally adding methods that are only used during unit testing may be evaluated and discussed.
But here getBalance() appears as unavoidable.

Upvotes: 2

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