import static org.junit.Assert.assertEquals;

import calculator.CalculatorPrototype;
import org.junit.Test;

public class CalculatorTestPrototype {
    @Test
    public void testSum() {
        CalculatorPrototype calculator = new CalculatorPrototype();
        int sum = calculator.sum(3,3);
        assertEquals(6, sum);
    }

    @Test
    public void testDivisionEven() {
        CalculatorPrototype calculator = new CalculatorPrototype();
        int division = calculator.divide(6,3);
        assertEquals(2, division);
    }

    @Test
    public void testDivisionOdd() {
        CalculatorPrototype calculator = new CalculatorPrototype();
        int division = calculator.divide(7,3);
        assertEquals(2, division);
    }

    @Test(expected = ArithmeticException.class)
    public void testDivisionByZero() {
        CalculatorPrototype calculator = new CalculatorPrototype();
        int division = calculator.divide(3,0);
    }
}

@@ -142,32 +142,70 @@
 type %7B%0A    @Test
+(expected = ArithmeticException.class)
 %0A    public void
@@ -213,11 +213,22 @@
 test
-Sum
+DivisionByZero
 () %7B
@@ -308,19 +308,24 @@
     int 
-sum
+division
  = calcu
@@ -334,45 +334,18 @@
 tor.
-sum(3,3);%0A        assertEquals(6, sum
+divide(3,0
 );%0A 
@@ -770,198 +770,1633 @@
 Test
-(expected = ArithmeticException.class)%0A    public void testDivisionByZero() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int division = calculator.divide(3,0
+%0A    public void testMultiplication() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int multiplication = calculator.multiply(4, 3);%0A        assertEquals(12, multiplication);%0A    %7D%0A%0A    @Test%0A    public void testMultiplicationByOne() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int multiplication = calculator.multiply(7, 1);%0A        assertEquals(7, multiplication);%0A    %7D%0A%0A    @Test%0A    public void testMultiplicationByZero() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int multiplication = calculator.multiply(7, 0);%0A        assertEquals(0, multiplication);%0A    %7D%0A%0A    @Test%0A    public void testMultiplicationCommutative() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int x = 10, y = 6;%0A        int mult1 = calculator.multiply(x, y);%0A        int mult2 = calculator.multiply(y, x);%0A        assertEquals(mult1, mult2);%0A    %7D%0A%0A    @Test%0A    public void testMultiplicationCommutativeByZero() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int mult1 = calculator.multiply(1, 0);%0A        int mult2 = calculator.multiply(0, 9);%0A        assertEquals(0, mult1);%0A        assertEquals(0, mult2);%0A    %7D%0A%0A    @Test%0A    public void testSubtraction() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int sub = calculator.subtract(5, 1);%0A        assertEquals(4, sub);%0A    %7D%0A%0A    @Test%0A    public void testSum() %7B%0A        CalculatorPrototype calculator = new CalculatorPrototype();%0A        int sum = calculator.sum(3,3);%0A        assertEquals(6, sum
 );%0A 

Add several test for subtraction and multiplication