Issue
I am trying to understand what is causing my test to throw a null pointer exception. I don't understand if I am not properly using mocks or something?
class OrderServiceImplTest {
OrderServiceImpl orderService;
@Mock
OrderDao orderDao;
@BeforeEach
void setUp() {
orderService = new OrderServiceImpl(orderDao);
}
@Test
void cancelOrder() {
Integer id = 1;
Order mockOrder = new Order(1, 1, null, null, 1, null, 1);
Order expectedResult = new Order(1, 5, null, null, 1, null, 1);
Mockito.when(orderDao.getById(id)).thenReturn(mockOrder);
Mockito.when(orderDao.save(expectedResult)).thenReturn(expectedResult);
Order actualResult = orderService.cancelOrder(id);
assertEquals(expectedResult,actualResult);
}
Here are the methods in the service class that I would like to create unit tests for:
@Override
public Order placeOrder(Order order) {
if(order.getLineItems().size() == 0){
return null;
}
for (int i = 0; i < order.getLineItems().size(); i++) {
if(order.getLineItems().get(i).getPrice().compareTo(BigDecimal.ZERO) < 0 ||
order.getLineItems().get(i).getName() == null ||
order.getLineItems().get(i).getName().length() == 0 ||
order.getLineItems().get(i).getQuantity().compareTo(BigDecimal.valueOf(1)) < 0){
return null;
}
order.getLineItems().get(i).setOrder(order);
order.getLineItems().get(i).setNumber(i+1);
}
return this.orderDao.save(order);
}
@Override
public Order cancelOrder(Integer id) {
Order orderToCancel = this.orderDao.getById(id);
if(orderToCancel.getStatusId() != 3 && orderToCancel.getStatusId() != 4){
orderToCancel.setStatusId(5);
return this.orderDao.save(orderToCancel);
}
return null;
}
Is it the methods themselves that need to be refactored in some way, or am I missing something silly?
Edit Here is the stack trace.
java.lang.NullPointerException
at com.tli.orders.services.OrderServiceImplTest.cancelOrder(OrderServiceImplTest.java:52)
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.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:210)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.util.ArrayList.forEach(ArrayList.java:1259)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.util.ArrayList.forEach(ArrayList.java:1259)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
at com.intellij.rt.junit.IdeaTestRunner$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:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Solution
From what you have shown, you are not initializing your mock's. There are cleaner ways to do this (which varies based on if you are using JUnit 4 or 5, so please specify if you would like help with that), but for the sake of finding the problem, can you try the following setup method:
@BeforeEach
void setUp() {
orderDao = Mockito.mock(OrderDao.class);
orderService = new OrderServiceImpl(orderDao);
}
Answered By - Jacob
Answer Checked By - Marie Seifert (JavaFixing Admin)
