JUnitMultiplicationTests

public class MultiplicationTests {

	@Test
	public void MultiplicationOfZeroIntegerShouldReturnZero() {
		assertEquals(0, Main.Multiplication(10, 0));
		assertEquals(0, Main.Multiplication(0, 10));
		assertEquals(0, Main.Multiplication(0, 0));
	}
	
	@Test
	public void MultiplicationOfOneIntegerShouldReturnItself() {
		int a = 25;
		int b = 35;
		assertEquals(a, Main.Multiplication(a, 1));
		assertEquals(b, Main.Multiplication(1, b));
	}
	
	@Test(expected = IllegalArgumentException.class)
	public void MultiplicationOfElementShouldReturnExceptionIfItsMoreThanThousand() {		
		Main.Multiplication(1000, 6);
	}
}

public class SumTest {

	@Test
	public void test() {
		int output = Main.Sum(5, 10);
		assertEquals(15, output);
	}

}

public class Main {

	public static void main(String[] args) {
		System.out.println("Welcome to the JUnit 4");

	}
	
	public static int Square(int x) {
		return x * x;
	}
	
	public static int Sum(int x, int y) {
		return x + y;
	}
	
	public static int Multiplication(int x, int y) {
//		if(x > 999) {
//			throw new IllegalArgumentException("X should be less than 1000");
//		}
		return x * y;
	}
}