MyBatis-Plus 使用mockito如何对mybatisplus的链式调用进行mock测试？

当前使用版本(必填,否则不予处理)

    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
    </dependency>

该问题是如何引起的？(确定最新版也有问题再提!!!)

问题描述： 使用mybatis-plus实现一个查询功能，针对链式查询方式，mockito单元测试该怎么写？ (查了很多资料都没有找到正确的办法，官网也没有提过)

业务mapper是这么写的： public interface IdRuleMapper extends ExBaseMapper {

}

单元测试用的mockito框架，是这样写的：

@RunWith(MockitoJUnitRunner.class) @SpringBootTest(classes = MainApplication.class) public class IdRuleServiceTest {

@Mock
IdRuleMapper mapper;

@Before
public void setUp(){
 }

@Test
public void testQuery() {
    IdRuleEntity idRule = new IdRuleEntity();
    idRule.setCurrentId(1L);
    Mockito.when(mapper.lambdaQuery().eq(IdRuleEntity::getIdType,"1").one()).thenReturn(idRule);
    IdRuleEntity idRule2 = mapper.lambdaQuery().eq(IdRuleEntity::getIdType,"1").one();
    Assert.assertEquals(idRule, idRule2);
}

}

但是执行报错。

重现步骤(如果有就写完整)

报错信息

java.lang.NullPointerException at com.gyd.service.IdRuleServiceTest.testQuery(IdRuleServiceTest.java:65) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:44) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:74) at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:80) at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39) at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163) at org.junit.runner.JUnitCore.run(JUnitCore.java:137) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69) at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38) at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11) at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35) at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:232) at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:55)