代码提升篇-IDEA单元测试详解

package tech.pdai.junit4.module;

public class Calculator {

    public int result = 0;

    /**
     * add.
     *
     * @param operand1 first param
     * @param operand2 second param
     * @return sum
     */
    public int add(int operand1, int operand2) {
        result = operand1 + operand2;
        return result;
    }

    public int subtract(int operand1, int operand2) {
        result = operand1 - operand2;
        return result;
    }

    public int multiple(int operand1, int operand2) {
        result = operand1 * operand2;
        for (; ; ) {                    //死循环
        }
    }

    public int divide(int operand1, int operand2) {
        result = operand1 / 0;
        return result;
    }

    public int getResult() {
        return this.result;
    }

}

package tech.pdai.junit4.module;

import org.junit.After;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;

import static org.junit.Assert.*;

public class CalculatorTest {

    private static Calculator cal=new Calculator();

    @Before
    public void setUp() throws Exception {
        System.out.println("before");
    }

    @After
    public void tearDown() throws Exception {
        System.out.println("after");
    }

    @Test
    public void add() {
        cal.add(2,2);
        assertEquals(4,cal.getResult());
    }

    @Test
    public void subtract() {
        cal.subtract(4,2);
        assertEquals(2,cal.getResult());
    }

    @Ignore
    public void multiply() {
        fail("Not yet implemented");
    }

    @Test(timeout = 2000)
    public void divide() {
        for(;;);
    }

    @Test(expected = ArithmeticException.class)
    public void testDivideByZero(){
        cal.divide(4,0);
    }

}