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

can anyone help?

Please help!

I've started the shell for the @Before fixture for these tests. See how Calculator calculator = new Calculator() 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. Don't forget to remove the Calculator instances from each test.

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 {

    }

    @Test
    public void addingMultipleNumbersProducesResult() throws Exception {
        Calculator calculator = new Calculator();

        int answer = calculator.addNumbers(1 ,2, 3);

        assertEquals(6, answer);
    }

    @Test
    public void addingSingleNumberTotalsAppropriately() throws Exception {
        Calculator calculator = new Calculator();

        int answer = calculator.addNumbers(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

In the @Before public void setUp() throws Exception{}

You need to add Calculator calculator = new Calculator(); between the curly brackets.

Then in each test remove the line for creating a new calculator.

By adding it to the @Before it will create a new calculator for you before each test rather than you manually having to create one.

thank you!