java - 无需使用 easymock 注入(inject)模拟

Question

我想使用 easymock 3.5 和 JUnit5 编写一个小示例，但是在尝试注入(inject)模拟时出现错误 (nullPointerException)...

这是测试代码:

package model;

import controler.BookEditor;
import org.easymock.EasyMockRule;
import org.easymock.EasyMockSupport;
import org.easymock.Mock;
import org.easymock.TestSubject;
import org.junit.Before;
import org.junit.Rule;
import org.junit.jupiter.api.Test;
import view.BookWindow;

import static org.junit.jupiter.api.Assertions.assertEquals;

//@TestInstance(TestInstance.Lifecycle.PER_CLASS)
public class BookTest extends EasyMockSupport {

@Rule
public EasyMockRule rule = new EasyMockRule(this);


@Mock
public BookWindow bookWindow;

public BookList bookList;

@TestSubject
public BookEditor bookEditor;

@Before
public void setUp() {
  bookList = new BookList();
  bookEditor = new BookEditor(bookList, bookWindow);
}

@Test
public void testBookCreation() {

  Book le_livre_de_la_jungle = new Book("Le livre de la jungle", "Rudyard Kipling",
        "Flammarion",
        "978-2081263246");
  assertEquals(le_livre_de_la_jungle.getTitle(), "Le livre de la jungle");
  assertEquals(le_livre_de_la_jungle.getAuthor(), "Rudyard Kipling");
  assertEquals(le_livre_de_la_jungle.getEditor(), "Flammarion");
  assertEquals(le_livre_de_la_jungle.getISBN(), "978-2081263246");

}


@Test
public void testDisplayBook() {
  bookWindow.setTitle("Le livre de la jungle"); //here is line 53
  bookWindow.setAuthor("Rudyard Kipling");
  bookWindow.setEditor("Flammarion");
  bookWindow.setISBN("978-2081263246");
  replayAll();

  bookEditor.setActiveBook(new Book("Le livre de la jungle",
        "Rudyard Kipling", "Flammarion", "978-2081263246"));
  verifyAll();

}

第一次测试没问题，但是 testDisplayBook 失败了，因为 bookWindow 为 null。

在我的 POM 中，我有这个:

<dependencies>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-api</artifactId>
        <version>RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-launcher</artifactId>
        <version>RELEASE</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.junit.jupiter</groupId>
        <artifactId>junit-jupiter-engine</artifactId>
        <version>RELEASE</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.junit.vintage</groupId>
        <artifactId>junit-vintage-engine</artifactId>
        <version>4.12.1</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.junit.platform</groupId>
        <artifactId>junit-platform-runner</artifactId>
        <version>RELEASE</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.easymock</groupId>
        <artifactId>easymock</artifactId>
        <version>3.5</version>
        <scope>test</scope>
    </dependency>

</dependencies>

这里是个异常(exception):

java.lang.NullPointerException at model.BookTest.testDisplayBook(BookTest.java:53) 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:389) at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:167) at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:163) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:110) at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:57) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83) at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77) at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)

谢谢。

Answer 1

在 JUnit 5 中，Rules 不能再使用了。你必须 use an Extension并用 ExtendWith 注释测试类或方法。此外，您必须使用 @BeforeEach 而不是 @Before ( See also the migration section in the user guide )。

更新:从 EasyMock 4.1 开始，EasyMock 附带一个 JUnit 5 extension开箱即用。

据我所知还没有正式的 EasyMock 扩展。 幸运的是 EasyMockRule 可以很容易地移植:

import org.easymock.EasyMockSupport;
import org.junit.jupiter.api.extension.ExtensionContext;
import org.junit.jupiter.api.extension.TestInstancePostProcessor;

public class EasyMockExtension implements TestInstancePostProcessor {

    @Override
    public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
        EasyMockSupport.injectMocks(testInstance);
    }
}

现在您可以注释您的测试类了:

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.extension.ExtendWith;

// ...

@ExtendWith(EasyMockExtension.class)
public class BookTest extends EasyMockSupport {

    @Mock
    public BookWindow bookWindow;

    public BookList bookList;

    @TestSubject
    public BookEditor bookEditor;

    @BeforeEach
    public void setUp() {
        bookList = new BookList();
        bookEditor = new BookEditor(bookList, bookWindow);
    }

    // ...