import org.junit.*;
/****************************************************
 * MyCalculatorTest - to test the class Calculator
 *
 * @author  Resendiz
 * @version January 2021
 ****************************************************/

public class MyCalculatorTest {

    /******************************************************
     * Test default constructor - no input parameters
     *****************************************************/
    @Test
    public void testDefaultConstructor() {
        Calculator calc = new Calculator();
        Assert.assertEquals("Calculator Value should be 0.0 at construction",
                0.0, calc.getValue(),0.1);
    }

    /******************************************************
     * Test add
     *****************************************************/
    @Test
    public void testAdd() {
        Calculator calc = new Calculator();
        calc.add(10);
        calc.add(20);
        Assert.assertEquals("If you add 10 plus 20 you need 30 as result",
                30.0, calc.getValue(),0.1);
    }

    /******************************************************
     * Test multiplication
     *****************************************************/
    @Test
    public void testMultiplication() {
        Calculator calc = new Calculator();
        calc.add(10);
        calc.multiply(4);
        Assert.assertEquals("If you multiply 10 times 4 you get 40 as result",
                40.0, calc.getValue(),0.1);
    }

    /******************************************************
     * Test division
     *****************************************************/
    @Test
    public void testDivision() {
        Calculator calc = new Calculator();
        calc.add(40);
        calc.divide(4);
        Assert.assertEquals("If you divide 40 by 4 you get 10 as result",
                10.0, calc.getValue(),0.1);
    }

    /******************************************************
     * Test clear
     *****************************************************/
    @Test
    public void testClear() {
        Calculator calc = new Calculator();
        calc.add(40);
        calc.divide(4);
        calc.clear();
        Assert.assertEquals("You should have 0.0 when you clear",
                0.0, calc.getValue(),0.1);
    }
}