Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

Java Unit Testing in Java How to Test Using Before to not repeat yourself

Challenge Task 1 of 1

I've started the shell for the @Before fixture for these tests. See how the Arrange part is duplicated in both tests, can you help me fix that please?

Use the @Before method to instantiate a new Calculator and use that instance in each method.

com/example/CalculatorTest.java
package com.example;

import org.junit.Before;
import org.junit.Test;

import static org.junit.Assert.*;

public class CalculatorTest {

    @Before
    public void setUp() throws Exception {
        CalculatorTest = new CalculatorAddNumbers();
    }

    @Test
    public void addingMultipleNumbersProducesResult() throws Exception {

        int answer = Calculator(1 ,2, 3);

        assertEquals(6, answer);
    }

    @Test
    public void addingSingleNumberTotalsAppropriately() throws Exception {

        int answer = Calculator(1);

        assertEquals(1, answer);
    }
}
com/example/Calculator.java
package com.example;

public class Calculator {

    public int addNumbers(int... numbers) {
        int total = 0;
        for (int number : numbers) {
            total += number;
        }
        return total;
    }
}

1 Answer

You need to create a new Calculator object

    private Calculator calculator;

    @Before
    public void setUp() throws Exception {
        calculator = new Calculator();
    }

Where do you place the new calculator