Testcase Mock

mock私有方法

https://automationrhapsody.com/mock-private-method-call-powermock/

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
 
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.mockito.Matchers.anyObject;
import static org.mockito.Mockito.mock;
 
@RunWith(PowerMockRunner.class)
@PrepareForTest(PowerMockDemo.class)
public class PowerMockDemoTest {
 
    private PowerMockDemo powerMockDemoSpy;
 
    @Before
    public void setUp() {
        powerMockDemoSpy = PowerMockito.spy(new PowerMockDemo());
    }
 
    @Test
    public void testMockPrivateMethod() throws Exception {
        Point mockPoint = mock(Point.class);
 
        PowerMockito.doReturn(mockPoint)
            .when(powerMockDemoSpy, "privateMethod", anyObject());
 
        Point actualMockPoint = powerMockDemoSpy.callPrivateMethod();
 
        assertThat(actualMockPoint, is(mockPoint));
    }
}

mock静态方法

https://automationrhapsody.com/mock-static-methods-junit-powermock-example/

package com.automationrhapsody.junit;
 
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;
 
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.anyInt;
import static org.mockito.Mockito.when;
 
@RunWith(PowerMockRunner.class)
@PrepareForTest({Utils.class})
public class LocatorServiceTest {
 
    private LocatorService locatorServiceUnderTest;
 
    @Before
    public void setUp() {
        PowerMockito.mockStatic(Utils.class);
 
        locatorServiceUnderTest = new LocatorService();
    }
 
    @Test
    public void testGeneratePointWithinDistance() {
        int distance = 111;
 
        when(Utils.randomDistance(anyInt())).thenReturn(distance);
 
        Point input = new Point(11, 11);
        Point expected = new Point(input.getX() + distance, 
                input.getY() + distance);
 
        assertTrue(arePointsEqual(expected, 
            locatorServiceUnderTest.generatePointWithinDistance(input, 1)));
    }
 
    public static boolean arePointsEqual(Point p1, Point p2) {
        return p1.getX() == p2.getX()
            && p1.getY() == p2.getY();
    }
}

如果static方法没有返回值
https://stackoverflow.com/questions/9585323/how-do-i-mock-a-static-method-that-returns-void-with-powermock

PowerMockito.doNothing().when(FileTransferUtil.class, "transferFile", any(FileStorage.class)
                , anyString(), any(FileStorage.class), anyString(), anyString(), anyBoolean(), anyString()
                , anyBoolean(), any(TransferType.class));

校验方法运行的次数

Object someObject = new Object();
verify(someObject, times(2)).equals(any(Object.class));

如果需要校验static方法的执行次数
https://stackoverflow.com/questions/18466198/how-to-verify-static-void-method-has-been-called-with-power-mockito

如果需要校验private方法的执行次数
https://www.codota.com/code/java/methods/org.powermock.api.mockito.PowerMockito/verifyPrivate

SomeClass someClass = spy(new SomeClass());
someClass.callPrivateMethod();
verifyPrivate(someClass, times(N)).invoke("somePrivateMethod", any(MethodParameter1.class), any(MethodParameter2.class));

java.lang.LinkageError: loader constraint violation: loader (instance of org/powermock/core/classloader/MockClassLoader) previously initiated loading for a different type with name "javax/management/MBeanServer"

https://stackoverflow.com/questions/16520699/mockito-powermock-linkageerror-while-mocking-system-class
尝试@PowerMockIgnore("javax.management.*")

校验运行时方法的参数

https://stackoverflow.com/questions/3555472/mockito-verify-method-arguments

public class SomeClass{
    public void someFun(){
        List<String> all = other.fun();
        List<String> wanted = new ArrayList();
        for(String id : all){
            if(check(id)){
                wanted.add(id);
            }
        }
        other.fun2(wanted);
    }
}

比如要写测试用例校验other.fun2(wanted)的参数是否是预期中的.
testcase可以这么些

ArgumentCaptor<List> argument = ArgumentCaptor.forClass(List.class);
verify(other).fun2(argument.capture());
Assert.assertEquals(argument.getValue().size(), wantedLength);

跳过流程中的某些方法

https://towardsdatascience.com/mocking-a-method-in-the-same-test-class-using-mockito-b8f997916109
使用spy

Stack map does not match the one at exception handler

https://systemoutprint.github.io/2017/09/06/PowerMock%E7%97%9B%E8%8B%A6%E7%9A%84%E6%8E%A5%E5%85%A5%E4%B9%8B%E6%97%85/